They're packaged together starting at $55.00 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=170176766471
One day left in the auction I certainly didn't think 55 dollars is unreasonable for season 1 alone, since as far as I know it's out of production, and you also get the movie. And it's the Christmas season. Surely there must be someone who likes Transformers but doesn't have the DVD.
$55 is pretty high if you ask me. You can get the entire series, all three seasons, on the Chinese DVDs for $90-$100.