AllProTools has the Porter Cable 7335 RO sander for $99.00 on sale right now.
The 7335 has a 3.7 amp motor, variable speed, 5″ diameter and a generally high build quality. It seems as if it may be a discontinued model in favor of the 7445, so prices may continue to fall over time. I’ve been using a yard sale score ($20!) 7335 for the past few years and it has never failed me in spite of having been mightily abused by the previous owner. Being able to hold it with two hands means greater control and less fatigue (although it is heavier) than palm type sanders.
Porter Cable 7335 [allprotools.com]