I should be a boat dealer; so my wife thinks and says, at times. I bought my first boat in 1975, when I decided to retire from the USAF. Since then, I've purchased five new boats. The best new boat purchase was a 2009 R21EC from Ranger. It wasn't perfect, but the after purchase support was great. I'm averaging more than one boat purchase a year; sometimes owning as many as three boats, at once. Somewhere around 60 boats in the past 41 years.
Having a heavy background in technical areas, I felt confident in my ability to judge the condition of most boats I encountered. After awhile, it became obvious two set of eyes with requisite skills were better than one. I never made a bad purchase, but found enough overlooked small things (after a few months of using a boat) to believe a good marine surveyor was worth his/her fee.
Two of my last three boats, I bought sight unseen. Boat number one: I depended on photos and the owner's statements, backed up by a marine survey. The second, I depended on photos and the owner's statements. Of course, it was a year old Ranger R21EC with a 30+ hour engine; delivered by the owner who lives about 150 miles away. It wound up with a bad battery, which he replaced.
Economically, a boat that is from one to five years old is the better buy than a new boat. And, one is likely to find equipment that is up to date. The older the boat, the more wary one should be. No matter what experience (or how much) one has, a good marine surveyor is important. Consult the marine surveyors' association for names, seek references; it's especially helpful to have personal knowledge about the surveyor. Private sale/purchases can be an advantage, if using a surveyor; and, one can manage the funding search by ones self.
I've visited a couple of manufacturing facilities when considering purchases of a new boat. That can be helpful in making a decision. No matter how good the reputation of a manufacturer, things can go wrong. It helps to see how the boat is put together. After purchase support is essential. One can't do too much checking and research on the dealer and the manufacturer. My personal experience leads me to believe there are very few really good support facilities out there. The marine industry is a far cry from the automotive and aircraft industries.
I'd buy a new boat, if what I wanted was only available new; and if I was convinced the support was OK. I'm still considering a new R23, a slightly used R25SC, or a R29. The used boats have an appeal, if I can find what I'd like from a private seller. In my state, private sales/purchases of used boats are not subject to sales taxes.