I'm really surprised at how easy it is to sell the older 2 cycle engines in the 25 to 50 hp range. And how hard it is to find decent ones if you want to buy them. They are often still very good engines, though decades old. They are lighter weight, and very easy to work on. Over the decades I've used 2 cycle engines, I can only count a couple of times when they've failed, and that was due both times to water in the fuel.
I bought a 1970's 25 hp electric start non-working evinrude a couple years ago on e-bay for 100 bucks. The engine wouldn't turn over. It was stuck. I removed the head, pulled the pistons, cleaned up the cylinders and cleaned the carb in about 4 hours one day. Put it in the trash can I use for old engine run-ups, and off it went. Put it on Craigs list and had a buyer in 24 hours at 500 bucks. Plus many other calls from folks who would have bought it. (I clearly should have asked more for it). The guy who bought it reported back after a year that it was still running great.
No need to be particularly fearful of older 2 cycles unless you just can't stand the smell or unless your waters are off-limits to them.
Some folks re-power from the 2 cycles to 4 cycle for fuel efficiency, but for a grand or two for older two cycles versus 5 or 6 times that for a new engine, you can buy a LOT of fuel and oil.
I do love my twin Suzies, fuel injected and 4 cycle, but, they came with the boat.