Ah, Schrödinger's toy box. It exists in a superposition of flawless and broken states until you open the box and collapse the wave function. You can always take your MISB toys to the airport, feed them through the security scanner and try and catch a glimpse on the screen. Or buy your own if you've got $5000 to spare.
The MISB issue is something I've thought about before, though in the context of buying rather than selling, and it's why I always make sure there's a returns policy when buying on Ebay. Australian consumer guarantees do not cover one-off private sales so I would say that in this case, as a buyer, you're out of luck unless the seller has a returns policy. Similarly, as a seller, I don't think you'd be obliged to provide a refund as long as you clearly state this up front.
If the item is sold as part of a business then your rights under consumer law should still apply and you are entitled to the seller's choice of refund, repair or replacement for minor problems or your choice of refund, repair or compensation for value loss for major issues.
Yep, in this case you're buying to re-sell so you (and not your supplier) are required to fulfil the consumer guarantees. Whether you can then seek compensation from further up the supply chain is your problem. The main issue would be in proving that it wasn't a one-off sale. Easy if you sell all 50 at once on Ebay, but harder if you sell in individual lots over a period of time. If you were careful, it would probably be more trouble for the buyer than it's worth to try and prove you were liable.Originally Posted by Trent
More info: Australian Consumer Law: Consumer Guarantees