Weeeeeeeeeeell Rim, you and I know repairing it is really a no-no if the cash is there for a new ride. With an old car, something else may/will pop up to drain the wallet.
So, what is the car worth in working order is the first question, what would the workshop offer for it as it is, then do the maths.
But alas, I have missed out the wifey element in the equation, so think I should have stayed quiet.............................