I sold a 125 that looked exactly the same last spring for under $2K.
Mine was a "2+2" engine, meaning it ran on 2 cylinders at low power & kicked in the other 2 when you hit the throttle.
If this motor works the same way... All I'll say is I mostly hated the damn thing.
It was fine at high power settings, but horrible in the harbour. I was embarrassed every time I cruised out with the engine trying to shake off the transom & belching oil smoke. The carbs have a habit of leaking when the motor is tilted up, so I left an oil slick at every launch. Something to check before purchase.
My 140 Suzuki upgrade burns a bit more than half the fuel of that old screamer.
Sure had a ton of power when you opened it up, though! And it never failed me.
If this one runs on all cylinders all the time, it'd be a lot nicer to own.
There is some bargaining room on the price, I'd think. From all I read before I bought the 125 they are a very powerful & reliable rig.
If nothing else, it'd probably work fine & get your buddy out on the water for a whole lot less than a new 4 stroke.
Just do all the recommended pre purchase checks. Depending on how long it's been sitting, I'd ask for a sea trial. Those carbs aren't cheap to overhaul. If they're gummed up you might not be able to tell until you opened it up for a while, under load. Low hours on an old engine isn't always a good thing.