Agford,
You're going to get a lot of replies about buying a good used machine, and I'm certainly not going to argue with that....if you can find one and know what you're getting. If you want a new machine, you're talking big box stuff. For the record, I bought a 46" cut YardMachine, an MTD product, from Home Depot in 2004. I mow probably three acres, and there are lots of rough places, and lots of trees to mow around. The first year I beat that thing to death. I was flying around the five foot circles of fence I use to keep the deer at bay. One of the neat features of this machine is a fairly tight turning circle. I can mow right against the fence circles. However, like all of the cheap machines, the wheels are hung on with cotter pins, and I several times jammed the wheels into ruts while doing the fast, sharp circles. I popped the front wheels off 3-4 times in the first two years, and eventually bent the front "axle", which is a formed steel pivot bar. I replaced the front axle and have been taking it a bit easier this year. It cuts the grass pretty well, has plenty of power, and does what I need it to do. It was about $1,100 in 2004, and the equivalent is still about that now. If it had a cast iron front axle and some better way to hold the front wheels on than little cotter pins, I'd probably have never had any problems with it. Heck, if I'd just been careful about hitting the ruts so hard, I probably wouldn't have had any problems. Thousands of dollars to cut grass just bugs me, and I'm not confident of my ability to recognize a good used high quality machine, so I did OK buying this one.
Chuck