Actually, the V6 is just as reliable as the I4 but with increased driveability.. By that I mean it's got plenty of power, near-zero vibrations even fifteen years down the line, and the transmission is also very smooth and dependable. I would not hesitate to recommend a gen 3 Camry, especially in V6 form.
The ONLY thing you need to be concerned about is making sure the previous owner was timely with oil changes. The V6 is not as forgiving as the I4 in that respect. I would pull the dipstikc and see if there's any varnish on it. If the previous owner was timely with oil changes, the V6 should be good for a loooong time to come.
Motor mounts might need to be replaced also. Check if there's a clunk when shifting from P > D or P > R or R <> D.. Assuming it's an auto. The dog bone mount (aka torque strut) is probably shredded too, I think I paid $70 at Toyota for that.
Once you get it I'd change the coolant, transmission fluid, and oil. If the previous owner has not recently changed the timing belt (it wouldn't surprise me if it was still on its original, some people just don't think about it) then go ahead and change that plus the water pump. Obviously I'd negotiate that into the price but that depends on what the price is at currently.
Oh and for $700? I'd probably buy it almost sight unseen. That's a worthy gamble IMO, as long as it runs. I don't even need a car but for $700 I'd add it to my insurance policy and look at it as a project car