Used wetsuit selection

My local dive shop is selling last years rental suits.
I weigh 190 and I'm 6 feet tall.
They have a large and extra large each of the following makes and models:
Aqua Lung Aqua Flex
Deep See Quantum Stretch
They are selling them for $140 to $160.
What should I know about used suits? Are they worth the money (look to be about 1/2 price)?
The suit I'm using now is a two piece that is at least 10 years old. I really like the stretchability of the new style suits.
Can you get used suits on eBay or that too much of a gamble?

You're probably an extra large.  Try it on first to make sure though. 

Fit is the one of the most important factors.  If it looks good, go for it.  You may get a good deal on ebay... only to find out it's too big or small.

If yer gonna buy on-line, you can probably do pretty well even with a new suit. But I would suggest buying used either from a shop or private party so you can try it on first - unless you can return the on-line purchase for a different size. I bought my first on-line suit this past year - exact same suit I had just finished wearing out. So I new how it would fit. That's the only way I would do it, unless I could return it. Fit is a big part of warmth.