Thanks to all for the helpful comments. I went ahead and made a deal for the two pieces from Modernglass.com and I feel quiet good about it. I'm sure the pieces will live up to their descriptions and photographs. And if they don't, their guarantee is quite good.
I broke a big psychological barrier, a self imposed price limit by buying these from a dealer and I'm not sure its a good thing. It is very satisfying to discover something somewhere and get a great price for it, but often they have little flaws or residue.
i have always felt the only way to actually learn about something like glass is to get it in your hand and look at it and really experience what it is like, You can do that without much worry if you are buying them on ebay for $20 because they have some flaw. You still see in actuality what the designer did and what the materials are and how the size suits the design. And if it has a chip on it, well I never see that from across the room...
These pieces will be the largest that I have and they will give a different overall scape to the glass I have. I hope it works out.
Thanks again for the thoughtful commentary.