When I ordered custom stamped discs from Gateway last spring, they quoted me $350 for 50 S plastic discs. If you sold them as "DGR Fundraiser" discs and made them $12/disc, you'd only need to sell 30 of them to break even. At the risk of insulting everyone's math skills, at $10/disc you'd need to sell 35. For mini's, they quoted me at $2/mini with a minimum order of $100. If you did that, you could then use that same, small custom stamp for as many regular discs as you want, but at "regular" price. If you sold them for $5/mini (seems steep to me) then you'd need 20 orders and at $3/ mini you'd need 34. You'd have to jack up the price on the regular discs to make money on them. Again, this is what I was quoted from Dave last spring, so I'm not sure if that's how it works anymore.
There seems to be some interest on here but I know from experience (no offence to anyone on here) that in situations like this, not everyone who shows interest is wiling to fork over the money. Either way, I'll bet it would be easier to sell 30-35 Wizards than 20-35 minis, assuming you can get the weights people want, but it would be some work either way.