I do think there is a market for this. I personally would be quite interested in hearing more details about it.
Speaking as a small-time developer, I don't have time to write my own libraries. When I started PPC development I got about half-way through my own graphics and sound libraries when I realized it just wasn't worth the time and effort when there were options available. Now, with GD being removed as an option, PF is all that's left, so any new ones that appear are welcome just for the sake of choice.
As for a pricing model, I implore you to support not only the big players who can afford a good chunk of change, but also the small-timers that either won't make much from their work or will give it away.
Allow for freeware titles to use your library for free.
Have a fairly high-priced site license for the big players. You might consider having a perpetual site license and a yearly site license. Maybe the perpetual is $10,000 and the yearly is $3,000, something along those lines. That way, the really big players can pay the big fee and never have to think about it again, and the medium players can pay the yearly fee and essentially spread the cost out over time.
For us small-timers, I suggest giving a choice...
(1) A relatively small one-time fee ($100-$250), but allow for flexibility in timing the payment. Let people license the library but not pay until a month or two AFTER the product is released. That way, I can secure a license now, relase a game in eight months, and pay in ten. This allows me to pay out of revenues and not incur an out-of-pocket expense, which is tough for us small-timers.
(2) The other option is a revenue-based model, maybe 5% of revenues for a year. This might be preferable for people because it removes any risk involved. If I write a game and it doesn't sell at all, there won't be a license fee I need to pay out-of-pocket at some point because the game failed.
Just some ideas off the top of my head.
