Clone Project: Magic Research

One of the problems with the alternative approach to experience that I came up with is that I can no longer base living expenses or the costs of magical research directly on experience. I'm working on a solution to the first one, but I've come up with what I think is an acceptable alternative to the latter:

Magical Research takes 1 week per spell level and has an initial investiment cost of:

• 2000 GP/level minimum,
• 5000 GP/level for spell levels 4 and 5,
• 10,000 GP/level for spell level 6.

Round to nearest 10,000 unless this would lower the cost.

This gives slightly different costs for spell research: 3rd level spells costs 2,000 GP more, 4th level spells cost 4,000 GP more, and 5th and 6th level spells cost 2,000 and 4,000 GP less, respectively.

I haven't worked out the chances of success yet. My initial thought was d20 +4, result of 20+ means success, double investment to add another +5 (triple = +10, etc.) But this violates my principle of keeping d20 rolls restricted to conflicts (attacks and saves against hostile spells)