If you're looking to buy *good* metal pads, you should be prepared to spend an unfortunately high amount, unless you get lucky.

I have two Cobalt Flux pads (with doubles bar) that I paid over $500 for the set used about a year ago. That was after a few months of looking.

Since I bought a machine recently, mine are actually for sale, although unfortunately I'm in Seattle.

To get a better feel for prices, since there's not many for sale nationally, you can try Google. You might get lucky and find something that isn't too far away, while you're at it:
https://www.google.com/#q=site:craigslist.org+%22cobalt+flux%22
https://www.google.com/#q=site%3Acraigslist.org+afterburner+DDR

If you wanted to trek up to Alaska, someone has a set for stupid cheap:
http://juneau.craigslist.org/vgm/4237721293.html

Good luck!

I didn't know anyone in Alaska played DDR.

Yeah, I've been scouring Craigslist and eBay for pricing.  There's a shitty DDRgame pad that some guy in Salem is selling but it doesn't have USB support and, well, it's a DDRgame pad.  Too bad music games kind of died after Activision murdered them with the Hero games.

I sometimes wonder how things would differ had Activision not milked the GH franchise to death. I still think dance games would be a hollow shadow of what they were in 2003/2005, but I think they would be better off than they are today. It's all speculation, though.

I think music games in general would be a tad better off.  Rock Band was doing fine, Konami was actually coming out with some new franchises, Technika is/was a cool concept.  I don't think the interest would last over time, but probably higher than it is today.

Didn't help that a lot of the hardware (arcade or home) is pretty expensive for anything of decent quality.