If it is a polyurethane coated pack cloth cloth type suit, I'd pass on it as there is no such thing as a good bilaminate used suit. They generally have a very short useful life and will drive you nuts with pin holes, delamination problems and seam leaks.
I'll second the vote for the O'Neil 7mm neoprene suit. I was well indoctrinated in the "Trilam and vulcanized rubber suits are better than those crappy neoprene suits" school of thought for the better part of two decades until I actually dove a modern neoprene drysuit, now I have an O'Neil that goes diving and two trilams that sit in the closet. Knowing how wrong I was on the issue for 20 years, despite the best of intentions, I would personally not consider the opinion of any neoprene suit detractor who has not actually dove one recently. (30 year old Unisuits with poor valve placement and ungainly hood and zipper arrangements do not count.)
Realistically you can get 5 plus years out of a $500 neoprene suit that costs 1/2 as much as the cheapest trilam available and costs 1/5th as much as a top end crushed neoprene or vulcanized rubber suit and 1/8th as much as a custom cut top end suit.
Personally, for the same initial purchase price I'd rather have five new neoprene suits over 25 years and spend $0 on maintenence than use one $2500 suit for 25 years and spend the last 20 years worrying about and paying for 5-7 latex wrist and neck seal replacements, 1 or 2 $250 zipper replacements, and 1 or 2 $200 boot replacements, plus the occasional pin hole and seam leak that needs to be repaired. The maintence costs alone over 25 years, would be enough to pay for 1 to 3 more neoprene suits depending on what you had to replace and how often.
The economics really are in favor of the neoprene suit and in my experience a neoprene suit offers more flexibility, more warmth and less hydrodynamic drag due to the closer fit allowed by the stretchy material.
