How much will a second hand centrifugal blower kit go for? Are there any big risks I should be aware of when compared to buying a new kit from a supplier?
The answer to that definitely varies a bit. It's going to depend on the age, condition and model being sold. Most people will sell their used kit for about 1-2k less than the new cost in general though. As far as risks, centri blowers are generally pretty robust and good for plenty of abuse before needing a rebuild so there's not a ton of risk. You're more likely to be missing parts than have it be a bad head unit. If anything is missing or broken, you're stuck paying full price out of pocket though. If you decide to go the new route for ease of install/less headaches and full support, shoot me a PM and I'll see what I can do on pricing.
Seen a couple buddies go down this path. In both cases we had to get complete parts lists for the kits and then buy everything that was missing. Most of it will be some random piece or pulley that nobody else will have but the kit manufacturer. If the kit is old or has been redesigned, replacement parts may be hard to find.
Do it right and you can wind up with a Big Bang for the buck.