Agreed on the wetsuit life, depends on how it's used, cared for, etc. Buying a suit without knowing that info is risky.
As far as Bonaire, it will depend on your comfort level (cold or warm natured?) and how many dives you'll be doing. Bonaire is a great place to dive 24 hours a day, so if you're going to be diving a lot, you'll probably need to layer by the end of the week, or wear a thicker suit. I wear a beanie to keep more heat in my head and that makes a big difference.
We love Bonaire, take a trip there every year! Have a great time!
Britt
CrazyScuba.com :fish: