For 5k, I would definitely be searching for a well-maintained, true commercial-grade mower. With two acres you'd never wear it out, and you'll get it done faster and in more comfort every time.
There is just NO comparison. Look around CL. 500 hours on a top commercial mower is comparable to 50,000 miles on a Toyota in my opinion.
As far as brands, you wouldn't go wrong with Deere, Scag, eXmark, grasshopper, and maybe Ferris' top models.
I'm partial to Kawi's in the commercial mowers we run.