A friendly note on Hambone's earlier post:
The Sabre by John Deere was their attempt to re-enter the less expensive consumer line up. It is a Homelite/Jacobsen design fron a HL/J line that Big Green bought outright. The 38" model had four manufacturer's service flashes in the first three months it was available, and several more since. The 42" has been somewhat more reliable, but is still nothing (physically or fiscally) compared to e "real" Deere.
Roper became American Yard Products, which then became Frigidaire Home Products, and has now become Electrolux Home Products. They also own Poulan now. They make almost every Sears tractor and a few other brands, but they are not Murray or MTD.
As evidence by EHP, companies in the lawn and garden industry have been swallowing each other up in the last few years, leaving essentially three tiers of tractors available: The lower tier (which are just fine for someone who just wants to mow once or twice a week and has no illusions about the units capability to do much beyond that, and it includes the Murray and MTD lineups, both those sold under their own names and store brad names like Yard Pro, Yard Man, etc..The second tier is your more usable, more durable line-up, primarily those by EHP and Troy-bilt (who themselves were bought up recently, but I don't remember by whom). They can generally be used with many accessories and have a longer life expectancy than some of the lower models. Remember that within most of these brands there are different classes of tractor, ie. lawn, yard, and garden. The third tier includes some very nice rigs, but you often pay an awful lot for something that most of us don't get a lot of satisfaction from using...including Ariens, real John Deeres, Kubota, Simplicity, etc...
In answer to the original question, just about any of the store brands from Lowes, Menards, K-Mart, etc..are going to be first tier tractors, but will meet your identified needs and price range. Depending on how it works out for the end user, he might consider the same the next purchase or move up to something else.