Hiawatha (what a great name!),
This is an awesome question. Hard to answer. But awesome. And I love how direct you were.
Googling math teacher salaries for Boston, they range from 50-100K. With the lower end more entry level and seniority the main factor for the range. Because of the job insecurity (the jobs did not exist in the past, and may not in the future), your positions will be a bit less attractive than the norm.
As a quick budgeting calculation, I'd figure (1.3)x(60k)x(2) = 156k/year for two full time positions. The ".3" represents a quick guess on a modest benefits package (at a minimum, you're looking at employer side of social security tax). Maybe round it up to 200k/year to include some slop (supplies, laptop, etc.--some of this could be modeled as one time, but to keep it simple, figure 200/yr).
If you can get a grant, I would be generous about budget guesses (make it 250 or 300). If you are operating with parishioner funds, the converse.
Thinking about the problem (I quite like Jochen's question), I would consider starting with one, versus two (unless you have access to grant money). Always better to pilot things.
Furthermore, I would argue for trying to minimize time spent on curriculum design (economy of scale argues against small programs designing things) and get something ready made. Probably something you buy. Some aspects of the first person, first year will need to be spent on program design/adjustment (I doubt you, your committee figure it all out), but I would differentiate this from full scale materials crafting.