Cub Cadet is owned by MTD, as is Troy Bilt and many other brands. MTD makes iffy quality stuff. Some of it is good but most is bargain basement. They've made a lot of money buying up good brands like Cub and Troy and putting their name on cheap stuff.

I took a look at the rt65 on cubs site and see it has the cheap Honda on it. We have some of those GC series engines on 2 inch pumps at work and I'm not very impressed with them. It's a throw away engine if anything breaks. If it were me, I wouldn't buy this tiller.

If you're gonna use it 2 hours a year in a small garden and are good about keeping it sheltered, changing the oil, and stabilizing the gas, this tiller will last you a few decades. If you're not so good with maintaining stuff, you may be better off renting when you need one. A gummed up carb fixed at the shop will cost you between 50 bucks and 150, depending on the shop.

As far as used, I bought a used BCS tiller and am very happy with it. It is among the best rear tine machines you can buy and it has a price to to prove it. Since I bought it used and can accept owning equipment more than 15 years old, I paid about 25% of the cost of a new one - just a touch more than the Cub you're considering. The best thing about them is the gas never has a chance to get old if you buy some of the other attachments. When you're done tilling, you can mow and chip branches, in the winter you can blow your snow. One engine to maintain and the attachments take up less space than each single purpose machine.

Good luck with your decision.