You're going about it right, for the most part. I would be surprised if you got information on a replacement sail drive without a few
phone calls. I did a web search for that once out of curiosity, and found pretty much zilch. If you're looking for an
installation price too, that'll be more difficult. Our local yard is good, but they'd never give you an
installation price, just an hourly rate plus the cost of the sail drive. Imagine them inspecting the boat to see what's involved and working up a detailed quote for $6,738.42. The average person, especially the average person who's just looking at the boat is going to say "thank you, no". How long do you think it takes the yard to figure out that's not how they should spend their time?
Other things, like
sails, running
rigging, and standing
rigging might be easier to determine replacement prices, but it takes a fair amount of homework to get answers.
One bit of wisdom that's oft repeated on sailing sites, and I'm in agreement with it,
is to buy the boat that's in better condition, as the one that needs the work is going to cost you as much or more. That's a pretty broad generalization, but it works for me.
Exceptions would be guys who can look at a boat, quickly determine what it needs, know where to get a good price on sail drive X, and do the installation themselves without breaking a sweat. If that's not you, get the better maintained boat.
I bought a 1996
Catalina 28 three years ago at top of the market pricing, and I would defy you to find a nicer one of that vintage. Still, it's a boat, and keeping it tip-top takes
money and effort. I'm glad I didn't buy at the lower end. I've done that before, and I wanted low hassle, good sailing.
Of course, the other trick is, if you pay in the upper range for a particular boat, is for it to really be a good boat. It takes a savvy, careful purchaser to accomplish that. An effective and detailed pre-inspection by the purchaser and a professional
surveyor from the best
surveyor in your area. I like to
head problems off at the pass whenever possible.
Best of luck to you.