I think patience may be the key in this case. If they're being blown out at discount stores, chances are there is enough inventory to satisfy demand. Collectors are just impatient, so right now the prices are high on ebay. But they also have a short attention span. I could be wrong, but in a year or 2 you'll likely be able to pick this up on ebay for roughly retail.
Now, there is some confusion...
According to the Q&A from this past winter:
*2)* Will the rest of the 25th anniversary DVD Packs and Vehicles see a wide release in Canada like the first wave? It's hard to build the MASS device when only 2 of the 5 packs have shown up at retail.
Yes, as Canada works through inventory, they will get to packs 3, 4, and 5.
But then from another thread from the Canadian Joe Con The Mike said the following:
"No new product is due in Canada until the Movie. That I DO remember them saying."
"Them" being Hasbro Canada.
Seems like it may be a bit of a contradiction, but maybe not. Maybe we'll see the DVD sets after the movie is out? Or maybe like in the US, stores are still trying to get through inventory of sets 1 and 2? Who knows?