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 13
45
95
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 6.79+ / day  19 193924 9898The cheapest 8 Rares used in the calculation | 4 bought Rares 242 8837(-91%) profit 781 attempts = 2,342 initial rares | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day |
| 3 bought + 1 crafted Rares 427 0373(-95%) profit 781 attempts = 2,342 initial rares | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Assassin's Godskull Harpoon Gun Rare 65, craft for 41 82Expand Recipe | |
| 2 bought + 2 crafted Rares 612 3620(-97%) profit 781 attempts = 2,342 initial rares | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Assassin's Godskull Harpoon Gun Rare 65, craft for 41 82Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 42 02Expand Recipe | |
| 1 bought + 3 crafted Rares 797 6867(-97%) profit 781 attempts = 2,342 initial rares | Cavalier's Aureate Speargun Rare 80, buy for 10 371.49+ / day | Assassin's Godskull Harpoon Gun Rare 65, craft for 41 82Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 42 02Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 42 02Expand Recipe | |
| 4 crafted Rares 983 0114(-98%) profit 781 attempts = 2,342 initial rares | Assassin's Godskull Harpoon Gun Rare 65, craft for 41 82Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 42 02Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 42 02Expand Recipe | Rampager's Krait Harpoon Gun Rare 80, craft for 42 02Expand Recipe | |
| Exotic Ingredients | |||||
| Precursor | Price to MF | Ingredient 1 | Ingredient 2 | Ingredient 3 | Ingredient 4 |
Rage Exotic Weapon Speargun 80 6.79+ / day 19 193924 9898The cheapest 7 Exotics used in the calculation | 4 bought Exotics 141 8376(-85%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Magi's Pearl Speargun Exotic 80, buy for 43 383.71-+ / day | Magi's Pearl Speargun Exotic 80, buy for 43 383.71-+ / day |
| 3 bought + 1 crafted Exotics 296 7540(-93%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Magi's Pearl Speargun Exotic 80, buy for 43 383.71-+ / day | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | |
| 2 bought + 2 crafted Exotics 451 6705(-95%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | |
| 1 bought + 3 crafted Exotics 625 9398(-97%) profit 139 attempts = 416 initial exotics | Berserker's Steam Speargun of Battle Exotic 70, buy for 24 784.06-+ / day | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | |
| 4 crafted Exotics 800 2091(-97%) profit 139 attempts = 416 initial exotics | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand Recipe | Cleric's Pearl Speargun Exotic 80, craft for 1 9227Expand 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)