depends on the extent of the work, the cost of the work, the time it would take to do the work and your comfort level with who would be doing the work.
Also remember that a discount in the price is only equal to the amount of the % of the cash you are putting into the deal. ie your putting 10% down payment The cost of the work is 10000 your cash value would be 1,000
So if you are going to do the work yourself which I recommend that way you know the quality of the work, it is my suggestion that you get cash back at the closing to do the work, that way you are getting the full value of the work that needs to be done.
Problem is that the lender may want the work done prior to closing, and if spelled out in the p&s it could raise red flags and will be taken into consideration in the appraisal.