Well, I recently bought a NT37. If this 37 didnt work out, we would most likely have a 32.
What I did was hire a surveyor that is familiar with the NT's and had him do a survey. He did a very good job. He saved me more money than I paid him after I brought his recommendations to the final negotiations.
I also hired a engine surveyor. That didn't work out so well. I should have hired a second engine surveyor, but I chose not too. My engine needed lots of maintainence items that were not listen in the surveyor report. The engine surveyor did say to have a full service performed on the engine, but I failed to inquire what that meant exactly. It was a rather lengthy and in depth process that also cost me thousands of $$. It's water under the bridge, but I will be more wary in future transactions.
Have the broker get you a list of recently sold NT32's from soldboats.com. Only brokers have access to this website. This will give you an idea of what they are selling for. NT's are not welling well right now and you are most likely the only one to put an offer in on the boat. Keep that in mind when making an offer. It's a tough balance to make a reasonable offer on a boat while not insulting the owner, but you have to do it nonetheless. I know the local NT dealer purposely prices the boats at least 10% higher for negotiating purposes. If I bought a boat from him (my boat was purchased elsewhere), I would start at 80% of the asking price and work from there.
Also go through the boat yourself and write down everything you think it needs. Dont expect even teh best surveyor to pick up everything. Check EVERYTHING to make sure its in working condition. Most NT's are well maintained, so hopefully its a shortlist, but there will be a list.
Also when you do a sea trial, make sure the owner runs it up to the full rpm (in gear) for 10 minutes or so and watch the temperature and the exhaust smoke.
I'm sure others will chime in with more advice.