There's actually another option for playing online. A few people have modified the program "Apprentice" (used for playing Magic: the Gathering) for LotR:TCG; most people I know that play online often use that. You can find information about that
here. It is somewhat hard-to-use, but most people agree that it's easier than keeping track of everything manually.
Oh, and in addition to eBay, there's a number of online merchants that sell LotR:TCG boxes at large discounts, if you're willing to buy in bulk. I personally use
Potomac Distribution, which is very cheap, but the minimum order is $100.