I have to point out thats a market strategy, buy the competition stock give them bad publicity(reviews) the competition runs out of bussines, start shelling the competition product + copy their desing..... Remains me of monopoly táctics, at léast thats how it sounds to me, one word of advice, contact the admins of e-bay, tell them everything in detail and ship the product, if you see it happends the above, well you have the backup of the admins, and also read the legal of the site, Its better to be ready.

and just to be curios.....what whas that product you said? Sorry cant helped, had to ask. Cheers