1) Listen to DrG
2) If you can get one elsewhere and resell it on Ebay you're laughing.
Buying though I would not unless there was a significant price advantage
and then I would not expect to get it at a price I'd accept as there would be
keen interest - I'd rather have a bunch anyway at once rather than small
deposits frequently.
Our ASICs are pretty much single purpose devices - you can't even really
password crack sha256 with them because it involves x like in this
formula - sha256(sha256(x)).
Mining shares/contracts might be worth a look at but due diligence must be done there.