Make up your mind early whether you want a tiller to last the rest of your life or a tiller to run for 5 years and die. I’ve had numerous tillers over the years on average wearing out one every 3 to 4 years. I use a tiller a lot harder than most people ever will. As a generalization, Craftsman rear tine tillers fall in the 5 years and die category.
I purchased a used but good condition Troybilt Horse rear tine in 2010. The tines are forward rotating. I wore the engine out and had to replace it in 2015. The rest of the tiller is in good condition and with a new engine runs like new. I was given a Tillsmith front tine tiller a few years ago that needed the engine replaced. I found a new Briggs engine for under $200 and have now used it for about 15 years.
The common factor in the tillers I own now vs the 5 and die types is that my current tillers have cast iron gear boxes. If you go to a store to purchase a tiller and see a stamped steel gear box, no matter the brand name, it is unlikely to stand up to years of grueling hard use.
One very important caution, the older 2 speed Horse tillers are geared and weighted in a way that can cause them to run away if used in compacted or stony soil. I strongly advise getting the 4 speed horse if you choose to go this route.
With a bit of craigslist watching, one can be purchased with electric start and a good engine for between $400 and $700. I like them enough that I purchased a second Horse a couple of years ago for my son to use. It has the 8 hp Kohler electric start engine. I paid $250 for the tiller, but had to do $150 of repair. It needed new tines, reversing disc, new pull cord, and a bit of adjusting. There are other good brands of tillers such as BCS.
Also, good sharp tines are important to any tiller. Replace them as needed and don’t skimp by purchasing the cheap steel replacements.
Here is a craigslist link for an excellent Troybilt tiller. If I lived within 200 miles, I would be there in a heartbeat even though I already have 2 good Troybilt tillers. This is the 25th anniversary Troybilt and it has about 100 hours use plus comes with the hiller/furrower and push blade. https://okaloosa.craigslist.org/grd/d/troy-bilt-8hp-tiller/6462277245.html