I am looking at a used HSU VTF-3 MK2 sub tomorrow and am curious what folks think is a fair price. The seller is asking $350 (orig price and what the MK4 sells for is x2 that at $699)
That's not too bad if the sub is in good condition. I definitely wouldn't pay over that though. Try to bring that price down a little bit if you can, especially if the amp hasn't been serviced or replaced. It's only a matter of time before the amp goes and that would be something like $250 to replace.
Any bass heavy material will do. It's going to be like an on-off switch, it will either work great or sound terrible/not work at all. By condition I meant stuff like scratches and scuffs, visual wear.