Even if the buttkicker kicks down 500w @ 4 ohms, 750w @ 2 ohms clean,is $250 a good price considering it has RCA input, crossovers, class D, fanless design.
Bash 500w is normally $228 {in sale right now for $159} and is 500W @ 4ohms,
not rated for 2 ohms.
Dayton 500w is $298 for 500W @ 4 ohms, not rated for 2 ohms.
Dayton 1000w is $398 for 1000w @ 4 ohms, not rated for 2 ohms.
These Bash - Dayton amps, who knows what they really do vs. specs.
I usually like to play it safe and assume they do less than advertised
if you were to run a stress test like the buttkicker went through.
Behringer EP2500, $350 street price, proven workhorse in the DIY sub world.
Tested recently {same test as the buttkicker} at 2000w @ 4 ohms, but
expect 1400w - 1600w under low voltage conditions. The amp will run into
thermal protect in minutes though. $100 more than buttkicker, but you have
fans, it's full range, not just a sub amp, may need a signal booster if you use
RCA to XLR input, no low pass crossover, but has more power than the buttkicker.
I guess the moral of the story is. In the $250 price range it's 'iffy' if you want
higher power. In the $350 - 400 price range you can feel comfortable that you
can drive the typical 1kw woofer. But if you have a 2kw-3kw woofer {or array of
cheaper woofers}, you will need to get into the $500 - $800 price range for a nice
amp.. and of course you can always go higher.. heh