You know the deal, someone release a product with resell rights and people grab (buy) it and start promoting it (keep in mind that the owner had a suggested price of say $149.97 and a day later some joker is selling it on Ebay for $2.00 or it winds up on some giveaway site being offered for free. I've seen this over and over again.
Package it - add more products/bonuses, etc... put your own spin on it. Sell it under a new name. Even create new product images (eBook covers, software boxes...) - Hannes Johnson
The only solution I have found is not to buy the product originally and just wait for someone selling it for 99% off (like you said, $2 on ebay). It's up to the original owner to make sure people aren't abusing the resell rights, and unfortunately it doesn't happen. I've learned the hard way that it is usually a waste of money to get in on those deals.
I would think you should analyze the entire problem right from square one rather than trying to remedy a potentially avoidable situation. Take more time to investigate the product and its resale potential before buying it.
There are a few problems with that... For one, if you're going to do all that work, why not get your own product and market it. I would say that adding the resell rights product into a collection as a bonus would be good, but don't focus on it. The big problem though (again, I learned the hard way) is that people will buy that cheap product for $2 and your product, thinking they are different. Then they'll be pissed and want a refund, and they may even start reporting you for copyright infringement and anything else they think of. Not to mention that selling it under a new name is probably illegal.
Dont want it to lose value? Dont offer resale rights and protect the code using http://www.zend.com/ or http://www.phpaudit.com