Depends..
If is gas, you'll lose your shirt in fuel costs towing it any distance.
Even if it's diesel-powered, a 3/4 is a bit light duty to tow much beyond short trips to the launch ramp or your local marina.
You also risk premature wear-and-tear of transmission, drive line components, engine, etc.
Can you do it? Probably, but I would err on the side of safety.
And then you have to be able to stop it......
I know it's your money..I understand things are tight..Just be careful it you start moving it around much.