Quick fixes before selling always pays off. Mammoth makeovers, not so much.
Call your Key2 agent in early to talk about the costs and the benefits of any major renos and the likelihood that they will pay off when it comes to selling. Do the updates that will pay off and get your top dollar. The key2 achieving this, is to give an overall well-maintained feel. Clean the curtains or buy some inexpensive new ones, make sure cupboard doors close properly, fix leaky taps, clean the grout in the bathrooms and complete all those unfinished jobs.