The older Trek 720s were pretty good hybrids. The even older 720s were great touring bikes, but this is not one of the touring bikes. I don't know your area, but $150 seems kind of high for this type of 720. I would guess about $100 max. for around my area.
But, this one would be a good choice for the type of riding you want to do. If the bike is your size and is in good condition, I'd try to talk the seller down a bit and buy it. I don't like the saddle cover, those things always seem to hurt, even though they are marketed to help resolve the pain.