FWIW I picked up an S3+ miner on Amazon for about $250. Even though the power/hash rate isn't that good ~.7watts/Ghs it runs well and very quiet relative to the newer miners.
Waiting for the upgrade boards too. :-)
That's a horrible price to pay for an S3. They used to sell for $70 or less on pretty much every site, and even now you can get a better deal for them on eBay. First search I looked for on eBay was a $180-190 S3 with shipping factored in. Not a great price but still lower than your $250.
It's still a quiet miner though, enjoy!
On that note, miner prices have come back down to Earth recently overall though there are still some holdouts on ebay who think $3k is a reasonable asking price for something like an Avalon 741... I sure hope people out there are not falling for it much but who knows.
It's certainly not a bad time to upgrade for all of us who buy second-hand miners and have the $$$ to do so.