I bought a boat that has been sitting a while and a buddy came over and looked it over and told me the steering was locked up and said "That's not cheap". Does anyone know why the steering wheel won't turn the motor?

cable rusted inside the cable housing.... new cables arent THAT expensive... installing them may be a booger if you have to remove the engine to get the cable inside the hull....

Can be unfrozen, take loose from the engine and try to 'work' a little and get some Lubricant inside cable. If you can get the inside to move enough to remove it, wire brush and grease up and reinsert it. Have done this on two different boats so know it can be done.--shu

note: don't force the steering wheel too hard as it can break, we used a pair of channel locks and a hammer from motor end, may be frozen in the motor 'tube'

Put your arms around the motor and try to turn it. If that works using your full body muscles it might be recoverable. Trying to turn the steering wheel hard will only break things. If you can get the motor to move and wheel to spin, put a Widget on the steering cable at the motor and grease it up. Suggestion based on personal experience many years ago. If you can't get it to move you'll need a new steering cable. The corrosion is probably in the steering cable housing near the motor. I searched the web for a Widget and they apparently go by another name now - steersman:
http://www.steersman.com/index.html

If it won't move spray some CorrossionX (red can) into the cable housing at the motor end and let it sit for a week or so and try again.

Well I unscrewed the bolt that holds the cable to the motor, and it now moves freely! Atleast I know it's just the cable. I will try the suggestions on fixing it or may just have to buy a new one. Guess I can get a new one at any marine supply house?

Yep...

none of that will work pm me i can help

havnt found one yet i couldnt fix as long as the insulation isnt broken