Postage Meters?

We’re going to be sending out a lot of review copies of books in the next few months and I’m dreading those sweaty trips to the post office (our local branch doesn’t have air-conditioning!?!). So I’m looking into getting a postage meter. They don’t seem to be too expensive to rent but I’m guessing the place where they really get you is the supplies.

Does anyone out there have experience with postage meters? Are they worth the money? I’m sure there are sites where you can get discounted supplies but my search has come up with lots of sites but I’m having trouble comparing prices and really getting an accurate picture. I was thinking of going with the Pitney Bowes mailstation but it looks like the Personal Post might be more common and therefore have better discount supply availability.