As another mower repairer, I have to agree with Rivets.
Every year steel prices go up, aluminium prices go up, plastic prices go up, land prices go up, transport prices go up, but mower prices go down.
So only one way that can happen, cheaper materials.
So while I am way down here in Aus so not all that familiar with USA prices I seriously doubt that you will get much of a mower for under $ 5,000.
Mower companies spend a lot on making them look & feel solid, but thick powder coatings on tissue paper thin steel does not a good mower make.
They look really pretty but don't last, even with meticulous maintenance you would expect to be looking for another one in 5 years.
GO into a mower shop and have a look at the prices of Honda Self Propelled mowers.
These are quality mowers that will last for decades, you won't get much change from $ 2000 on the top line models .
If that is all your budget will stretch to go out and look for a used mower with a manual blade engagement and a vari-drive transmission.
Even then you will be looking a smaller decks 36" to 42" which will make mowing your property quite a chore.
I really like the Cub Cadet 2000 series, they will take a pounding, fall apart & keep on running, but Cub discontinued the spindles a few years back and they are getting hard to find.
Quality mowers use tapered roller bearings in the spindles ( as the above do ).
Slightly lesser quality use 6300 series deep groove bearings
Cheap ones use 6200 series bearings.
Also look at the blades, the wider & thicker the better.
The above mentioned Cubs use 3" wide blades that are 1/4" thick and they will last till they have been ground back to nothing.
Husqvarnas use 1.875" wide blades that are 1/8" thick and use the curved shape for strength.
These I regularly replace bent & twisted but rarely worn out