You did not say what your limit was that you would like to spend, nothing worse than first Boat a Piece of SXXX. Older Pro Line Good Hull, that being said you have to get in boat and walk around, checking for soft spots, check fuel tank ,leaks /full of crud from sitting and gas is flat. I look and see if Boat has a CURRENT Registration if not WHY???
As for epenses ,if you can change lower unit fluids, change impeller you will save a few bucks doing that your self, where are you going to store boat, back Yard, storage area , Marina will add to expense ,towing insurance (Sea Tow Boat US ) Boat ins, did not say but how is trailer, You need to take A current Boat owner along with you when looking for first boat unless it is john boat with 10hp.
One other point to consider is Fuel Cost, In my view a smaller boat such as 18/19 with a 115 would be a better choice as a 4 Holer (V-4) cheaper to run tha 6 holer unless a four stroke,my 19 ft century 3 can fish with No Problem sure with 21 can add another Guy with bigger engine , .
Right now to many boats out there for sale and with winter coming on , pass on this Rig and look for little better set up, so perhaps you have to go up another $1000 in purchase price , hell you can find Junk any where almost Free . Remember dont buy the first thing that comes along , put some miles on vehicle looking and searching , Oh we didnt cover what are you going to Tow with, dont tell me a mini van,
Good luck in search, hell thats half the fun looking at JUNK cause it is readily available for new owners coming down the Pike. As others will tell you you will know YOUR BOAT when you see it.