I can't say about walmart but we bought ours at sears, we was able to get a 3 year extended, which is a good thing, since the book that came with it didn't show everything and we ended up damaging it the technition didn't get mad because I showed him the book and he said it was stupid for them not to show where all the nuts are and to now advise you on how to move it without breaking the plastic parts and the bolts that held the lid,
with this extended warranty we get once a year total inspection and adjustments and mainteance care, the technition told me the first to go is the tread and it costs 80 dollars for it plus installation, of course I run on mine, if all you want to do it walk a cheapie is probably fine.
RR