[Cozumeleno]

I put together both the T205 (208-card set) and T206 (520), and would agree with what Marc said. In summary, the T206 set is more expensive because of the sheer volume and fewer expensive cards in total.

What I'd add is that some of the variations and tougher cards can be difficult to find. I had a tough time with Graham Cubs, which I didn't see on eBay for many months, for example. Wilhelm (even the corrected version) isn't plentiful, either. And some cards, like the Joss, can be extremely hard to find in lower-grade condition - I didn't see one that wasn't outrageous for many months. It's a little different from T206 in that you won't always find the tougher cards on eBay at any given time - let alone in the lower grade that you want.

My advice to you would be to pick up the tougher cards when you can fit them in your budget instead of trying to buy only commons at first. Some of them can be too tough and it may be several months before you find another in that condition. If, for example, you find a low-grade Joss or WaJo, I'd jump on it. Cobbs/Mattys are generally always out there so it's less of a concern.