Interesting discussion, I can relate to both the thought that a tractor is a luxury and justifiable due to age. When young and if totally honest, more ambitious, I push mowed a full acre. That seemed a better way to stay fit than to pay for a gym membership like many friends were. My luxury came in the form of a self propelled walk behind.
Then I found a good deal on a used Cub Cadet that I loved, it had only 12 HP from a Kohler K series. Then later I bought two John Deere 318's and a 430. With all these I quickly came to understand the major differences between "lawn tractors" and "garden tractors". For the price new, I doubt any manufacturer of garden tractors will risk the long term reputation and use a less than worthy engine. This is not true of the lawn tractors sold in the $2000 range new.
This is true of many other components, from drive train through steering and deck. I can't lift the JD 60" mower deck and suspect it alone may weight nearly as much as some lawn tractors. The lower cost comes with lower service life.
That's why, although I purchased the 318's new (another story), I now buy used garden tractors. There are many folk who simply schedule to buy a new mower every couple years, most of these owners have them dealer maintained and don't blink at the cost. These trades, even though seemingly expensive, can be a bargain with expected lives measured in decades. My 318's were produced in 1985 and remain fantastic mowers with added utility today. If these engines crap, I have already purchased a 26 HP Honda and 24 HP Kohler for repowering.
I've also seen both auctions and Craigslist bargains. It may take some shopping time but when retiring, farmers liquidation auctions often include potential bargains, also when we of the aging class downsize or leave a widow who eagerly sells their garden tractor.