Rowing Machine/ Elliptical Machine

with which one can you get a decent sturdy home model for $500 or less?

Depends on your definition of decent, but my fiancee has a really nice eliptical machine that was around $4-5 hundred when new (and which she got free from someone who upgraded to a new one). The arms move for upper-body workout as well; I'll look this evening to find out which brand/model.