Hmmm. I am a DIY guy from way back.
For example I designed my current house about 25 years ago. It is undoubtedly the ugliest house in the street but, boy oh boy, is it strong!
In the past, I have gone mad in refibreglassing old canoes and small boats and even built a trailer for a 16 ft canoe from scratch with all new parts. Like many of my DIY projects, that was probably one of the most expensive things that I could have done, considering the few number of times that I used it. It now lies rusting away around the unseen side of my yard. Sold the canoe - and kept the trailer - what the heck! - every yard needs an eyesore somewhere.
Lots of the DIY things that I have done were for economic reasons but after years of crawling under cars doiung really mongrel jobs like replacing ball joints etc with the most basic of tools, I made an oath to myself that once I hit the ripe old age of fifty, I would never again crawl under a car. Six years after hitting fifty I have mostly honored that pledge.
Likewise, I decided that at about the same age, i would never trust my life to my own mechanical skills in a boat - 'cause I swim like a wind tunnel tuned lead sinker.
The net result of that is that whilst I will potter arount the boat installing add-ons like power sockets, downriggers, extra rod holders, GPS cradle etc, I would not put a spanner on the motor.
So I drop $50 each fortnight into an online savings account and when the boat needs servicing or mechanical attention, i just use those funds get it done without ever quibbling at the price. I know that I pay top dollar for the mechanic but I don't care as I would trust their skills far more than my own.
Having said that though, I still could not stop myself getting a factory workshop manual "just in case" and doing regular easy jobs like greasing the various greasepoints every few trips, repacking wheel bearings, replacing worn skid plastics and rollers on the trailer, and regularly fixing those bloody trailer lights - but everyone does that latter one, don't they?!