Watch the auctions. I picked up an old Beaver 7" for ten bucks, it was heavy enough to stay put when I was cutting yet portable. Sold it for $25 when I got a contractor 10" for free.
I rented a so called 'contractor' model (Ridgid)when I re did our travel trailer. The thing was junk. It was too light, insisted on tipping when I was trying to rip. I had to remove the riviing knife, the wood jammed and kicked back, and the fence would not stay square.