I bought a decent set last year for < $40 last year via
eBay auction. Just keep your eyes open for when they're posted via notification from
eBay and bid at the level you're willing to pay. If your bid is reasonable, its pretty likely you'll eventually get a set at that price. There's certainly no lack of them on the market so patience can be your friend. If you search on
eBay for completed transactions, you can get a good sense of what they're selling for.