I am not sure of these numbers. I am 100% sure the listed ingredients are the cheapest to make the desired precursor, but I am not 100% on the average number of tries to get the precursor (the current estimate is from other people publishing their results - mostly from reddit's Nugkill).
Spirit Shard and Karma Items excluded (Allow SS and Karma items)
The Bard
Carcharias
Chaos Gun
The Chosen
The Colossus
Dawn + Dusk
The Energizer
Howl
The Hunter
Leaf of Kudzu
The Legend
The Lover
Rage
Rodgort's Flame
Spark
Storm
Tooth of Frostfang
Venom
Zap
Random Precursor from weapons
Random Precursor from any rare item
1 Mystic Forge Stone currently costs 14
31
90
to buy (It's only recommended to use it to take the place of an item worth more than that, or you get them for free)| Rare Ingredients | |||||
|---|---|---|---|---|---|
| Precursor | Price to MF | Ingredient 1 | Ingredient 2 | Ingredient 3 | Ingredient 4 |
 Rage Exotic Weapon Speargun 80 5.39+ / day  25 961030 4499The cheapest 7 Rares used in the calculation | 4 bought Rares 261 1526(-90%) profit 781 attempts = 2,342 initial rares | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day |
| 3 bought + 1 crafted Rares 327 0263(-92%) profit 781 attempts = 2,342 initial rares | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Assassin's Godskull Harpoon Gun Rare 65, craft for 22 40Expand Recipe | |
| 2 bought + 2 crafted Rares 611 3666(-96%) profit 781 attempts = 2,342 initial rares | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Assassin's Godskull Harpoon Gun Rare 65, craft for 22 40Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 59 71Expand Recipe | |
| 1 bought + 3 crafted Rares 895 7068(-97%) profit 781 attempts = 2,342 initial rares | Berserker's Krait Harpoon Gun Rare 80, buy for 11 152.05+ / day | Assassin's Godskull Harpoon Gun Rare 65, craft for 22 40Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 59 71Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 59 71Expand Recipe | |
| 4 crafted Rares 1,180 0470(-98%) profit 781 attempts = 2,342 initial rares | Assassin's Godskull Harpoon Gun Rare 65, craft for 22 40Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 59 71Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 59 71Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 59 71Expand Recipe | |
| Exotic Ingredients | |||||
| Precursor | Price to MF | Ingredient 1 | Ingredient 2 | Ingredient 3 | Ingredient 4 |
Rage Exotic Weapon Speargun 80 5.39+ / day 25 961030 4499The cheapest 8 Exotics used in the calculation | 4 bought Exotics 148 8088(-83%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Rabid Pearl Speargun Exotic 80, buy for 49 094.15+ / day | Rabid Pearl Speargun Exotic 80, buy for 49 094.15+ / day |
| 3 bought + 1 crafted Exotics 281 6984(-91%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Rabid Pearl Speargun Exotic 80, buy for 49 094.15+ / day | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | |
| 2 bought + 2 crafted Exotics 414 5879(-94%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | |
| 1 bought + 3 crafted Exotics 575 2270(-96%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 22 421.23-+ / day | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | |
| 4 crafted Exotics 735 8660(-96%) profit 139 attempts = 416 initial exotics | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | Settler's Pearl Speargun Exotic 80, craft for 1 7681Expand Recipe | |
Help and Info:
● Gives a list of all precursors for you to select, then tells you the cheapest ways to make the precursor you selected by throwing them into the Mystic Forge.
● The top combination will have all purchased ingredients. The second combination will have 1 crafted and 3 purchased ingredients. The third combination will have 2 crafted and 2 purchased ingredients. The fourth combination will have 3 crafted and 1 purchased ingredients. The last combination will have all crafted ingredients. You can pick which you want to use.
● 'Precursor' is which precursor is being made, and the buy order and sell listing prices for that precursor.
● 'Price to MF' is how much it costs to buy all the ingredients that will give you 1 precursor (on average). % profit is if you're selling it. The price and number of items assumes you re-MF any products of failed attempts.
● 'Ingredient 1,2,3,4' is which are the cheapest ingredients to throw into the forge and how much to buy or craft them.
● These are all averages. That means there will be times when no precursor comes out for 1000 attempts, and times when you get 2 in a row, for example. The strategy is that with a statistically significant amount of tries, you will observe the average return.
Precursor Drop Rates:
Drop rates is from research posted on reddit from the production of 289 precursors.
1 in 5 promotes rare to exotic, but appears to have less chance of getting a precursor
Average level of ingredients needs to be at least 75 to guarantee a level 80 (and thus, a precursor)
1 in 139 attempts produces a precursor from exotic (start with 416 exotics, including throwing failures back in)
1 in 781 attempts produces a precursor from rares (start with 2,342 rares, including throwing failures back in)