You may want to look at a Scag's Freedom Z. It's made for exactly your type of usage, basically someone with a few acres to mow vs. full commercial use. I've had a 52" Freedom Z for about 8 years now and haven't had any issues with it, mowing ~ 4 acres. It was ~$5000 new. The thing is, when you are only mowing a few acres a week with a good zero it goes very quickly. I only have ~ 180 hours on mine right now. A commercial one is made to be used 1000-1500 hours a year, so it will last indefinitely in a low use application, but as you found out you pay big $ for that durability that you really don't need in a residential situation. The good thing about Scag's is that they are a well-established company, so you can count on long term support for parts & stuff.
I think they now even have a model with a few less features than the Freedom Z as well. The only drawback's that I see with the Z is that you sit a little lower, so if you are mowing an area where you have some dirt & weeds you tend to get a little dirtier, but the plus is that you can get under low hanging trees and stuff easier. I actually took the top roll bar off mine since I'm mowing completely flat ground. My previous mower was one of the early Scag 3 wheel mowers with a 61" deck out front and you sat over the rear wheel. It worked great fro getting under stuff and you stayed clean, but the Z is a WAY faster mower. I can mow the place in less time with the Z, even though it has a deck that's 9" narrower.