Have to agree with some comments above.
I have built, repaired and recapped a bunch of gear myself.
firm believer that everything is repairable. And depending on where the cap sits in the signal path, it’s an opportunity to put a higher quality cap in its place.
I would tend to trust your service person and ask what can be done to put a higher quality cap in its place - again depending on where it is in the signal path.
Parts Connexion has a large inventory of higher end capacitors to choose from.
From your description, this should be a simple fix.
I just picked up a Krell KSA 200 that was DOA that I got for a good price. Have no idea what is wrong with it, but suspect it’s a minor thing. Again, I’m a firm believer in the idea that things can be fixed. Especially gear that was properly built to begin with.
I would imagine this would not be a costly repair for you, and would be well worth the expenditure.
And I’m curious how you would compare the ML with the 3150? A friend recently picked up a 3150 for a decent price ( it was in rough physical condition, but was working properly). It actually died on him and he freaked out, but after some trouble shooting, it was a simple replacement of one of the rail protection fuses.
Somtimes, it’s just not a big deal to remedy. Fuse or capacitor, it’s just a simple part.
Good luck!