8 btc is quite a good deal if he can get it. Sadly though the pay off @ 4.5 TH with a price of 8 btc is pretty grim. I'd offer 5.8 btc. This seems like a fair price (at least for the buyer) but I doubt he'd want to take the loss.
Can't you just mine with it? Are you lacking in power or space, or cooling?
I have plenty of power and cooling as I built a nice server room in my basement, I just don't need the extra expense as electricity is costly in my area, and was expecting 6TH/s instead of 4.5 and not the additional 500 watts, plus I have a lot of miners in the cloud at the moment, and want to pretty much have everything virtual. so that's really the reason for the sale.
I also have:
(2) S2's 1Th/s each
(2) S3's 441Gh/s each
(1) Dragon Miner 1TH/s
(2) Gridseed Blades with all accessories
All on-hand, for sale as well, which are all in mint condition with all the original packaging it came in.
The payoff may look grim at the moment and I understand you don't buy something thinking maybe the price of BTC will rise (which it does, and it falls as well) so it's always a gamble. But if someone gambles correctly, or has cheap or free power and BTC rises, they are in a win-win for the life of these miners.
Plus my wife would like me to get all the noise out of the house
So as far as offer's I'm flexible but I also don't want to take a loss.
eBay for me is a last resort, since I do not like their policies with Paypal and charge-backs which are usually automatically in the buyers favor especially with electronic goods and mining equipment which they know nothing about.
I have been an eBay member since they opened and have 100% rating, but that wouldn't stop some scammer from buying it and doing a charge-back....once they incorporate BTC into the system, maybe it will be different, maybe not. But for now I like buying and selling my equipment within the community using trusted escrow services.
Thanks!