It is probably O.K., but you might want to consider getting it directly from the manufacturer. Here is the web page where it is sold for the same as the auction's starting bid price:http://www.mefferts-puzzles.com
Meffert's also ships for free. It usually takes about 1 or 2 weeks to receive it. (...which means that you would have it in about the same timeframe since you don't have to wait for the end of the auction at Mefferts.)
Remember also that you will probably pay more on Ebay unless you are the only bidder. If you pay the Buy-it-now price, it will cost you $22 more than at Meffert's.
Ask anyone on the twisty site, Meffert's is an excellent, reliable source for this and other puzzles.
I hope this helps!