Why 10" woofers specifically? Wouldn't it make more sense to set a goal for the size of the enclosure and then pick a woofer or woofers that will work with that, regardless of whether they are 10", 12", 15" or whatever. Or perhaps you have a specific reason for wanting 10's?
The reason I ask is that you can probably get more bang for your buck with two 12's or a single 15.
I assume that since size is an issue and you're planning on multiple woofers that you'll be building a sealed box.
I'd consider a pair of Stryke AV12's in a 65L box with a 500 watt/channel pro amp. The woofers are $175 each and
www.musiciansfriend.com has the Nady SPA-1400 amp for $299 that puts out 2 * 500W @ 4ohms. That would be just inside your budget but I'm not sure if Stryke has AV12's on hand right now or not. If not you'd have to wait until their AV12 mk3 comes out.
Or perhaps a Blueprint 1503 in a 50L box with 1000 watts. That woofer is $240 from Acoustic Visions and the Nady XA-1100 is $279. You'd probably also need an equalizer with the Blueprint driver because of the high voice coil inductance. But still, we're talking about a heck of a lot of performance for your money here.
