Shawn,
I bought a 100 Years pre-production proof plate (how's that for alliteration?) several weeks ago. They're about 3.25" x 3.5" inches and very nice. I figure they're limited editions of 10, so you really can't go wrong at $25 can you? Besides, they're really beautiful. I got the Pooh Discovers the Seasons plate, and although I'm not a huge Pooh fan, it looks great framed with my 4 Seasonal Pooh pins from last year at WDW.
I've noticed the prices on these have begun to run up, so I guess I'd be less likely to dip my toe in the water now, but it's still a great collectible for a pin collector. I guess it's like anything pin related. Buy what you like, pay what you think it's worth. I feel like I definitely got my $30 worth (with shipping).
Let us know if you decide to take the plunge.
Jim