Ask your realtor, but I wouldn't paint them for resale. Buyers will have more options with the wood cabinets.

I always prefer wooden cabinets painted - always.

I have been using walnut oil on wood from marred cherry furniture to ruined oak parquet floor tiles. It's inexpensive. It certainly won't hurt your cabinets. Buy it in the salad oils at your local grocer's. Don't sand or anything. Just wet a paper towel with the oil and rub it on. Walnut oil, unlike other edible oils, will dry in about 24 hours. works lot like tungsten oil with WAY less work.

It would be helpful to see a color photo of your kitchen, but I agree with periksencat about making do with what you have. Since light blue is the complementary color of brown and yellow, I would suggest you avoid blue and opt to paint the kitchen walls white. If you cannot afford a backsplash, paint the wall between the wall and base cabinets with a paint that can be washed easily and let the new homeowners decide what they want to do with the kitchen. Having the appliance colors harmonize and making the room light, bright, and uncluttered will go a long way in making a good impression.

Ask your agent.