tell me about it... white sensors doffs are selling for 1 mill+ on the exchange! And almost never dropping from recruitment missions or doff packs! And my fleet is still 15 short! (ok, we COULD dump 20mill into the exch and get it done, but who's to say we won't just get another mission just as expensive tomorrow? :/ I won't ruin myself to get the base to T2, and then get stuck.
I would almost rather see the ability to put higher tier against the project, such that they count for a higher quantity of the total.
For example: white = 1, uncommon = 5, rare = 25, purple = 125
This is following the pattern it takes to upgrade using the doff assignment change, the actual value could end up being less, but this would be the max.
Say you needed 30 conn officers. You could then do this with 30 whites, or just 6 uncommon, or 1 rare and 1 uncommon, or 1 purple for a huge waste.