Well if you are sure about your size, there is always the online retailers or ebay. Drysuits can be had on ebay for less than $400. My buddy picked up an immaculate Viking with undergarment for that much.
I have only one cold water wetsuit, that I can comment on. This is a Parkway 7mm one piece with intergral hood. I like it because it works well (it's a good fit so circulation is minimal). The integral hood in particular, keeps in a lot of heat and reduces the number of joints/openings. Plus it was relatively low cost.
I'm not convinced that there is a huge amount of difference in performance between big brand name suits and ones like the Parkway. To me the thickness and fit are more important. Also the more stretchy the suit is, the more it will tend to compress at depth and hence the colder it will be. That's why I was somewhat suspicious of suits that claimed to be "very" flexible.