Not if you want to make money.  But if you want to help secure the network and make some of your money back, go for it.  Try paying for it in fiat and not BTC though.

If you paid for the mining equipment in Bitcoin, yeah probably. But if you buy it in fiat? Maybe. You're probably better off taking that money and just buying Bitcoin and investing it in ASICMINER or another company.

I used this mining calculator: http://btcinvest.net/bitcoin-mining-profit-calculator.php?diff=19339258.272387&dcosts=2000&diff_mincrease=10&blpbtc=25&dhsmhs=2000&btcusd_mincrease=10&btcusd=105.55&dpowcon=1000&dleadtime=0&pcost=0.25&calcweeks=48&action=calc

And that's at 10% difficulty increase/month, which is very very conservative in my opinion.  You probably shouldn't buy this. You'd be better off taking the money you were going to spend and converting them to BTC and then buying shares in a company like ASICMINER.

I have a Mac Pro (with a 5770) that I would love to try this out on.

Any reserve? Starting bid?

Graphics cards generally use a lot more than ASICS, like the Block Eruptor USB.

I believe Coinbase uses a recent average of the prices whereas some of the exchanges, such as Mt. Gox, use the most recent price to determine what you can buy it at.