People would like to ask for repair credit back. In our area the most sellers will do is provide an inspection report and want buyers to release ALL CONTINGIENCES (except loan) to start an offer.  You as buyer decide what you have to pay to get in working order. It is an entirely sellers market.

If it ain't broke, we don't fix it no matter what they say.

When the system is still functioning, there is nothing to repair; however, Sometimes buyers will ask for an allowance at closing.  Usually, we try to dinf out the age of appliances, roof, A/C, water heater, etc ahead of time so there are no surprises.

I have had buyers ask for credits towards the future replacement of a major system.

I try to set up expectations, if it is working, sellers have a hard time replacing X (for example HVAC that is 20 years old but working properly).  I remind buyers (I am mostly a buyers agent) that we got them a home warranty (paid for by sellers) that will cover it should it fail the first year and my advice is keep the home warranty until it does die.  We know it is on the end of its life.  Another good reason for seller to buy a home warranty for buyers at only $500 will save them more money then they realize while conducting the buyers inspection period.

They don't ask for repairs but occasionally ask for a credit toward replacement.

Hi David -- I don't know the percentage but buyers have been known to ask for a lot of things --- that list is seemingly endless.   

More information needed.

If priced properly and THE buyer had the opportunity to see all the other buyers going through the house, the options available to the seller greatly increase and the outcome for the buyer will be more predictable.

ALL buyers will ask for a concession with the caveat from their agent, "Please don't kick this offer to the curb immediately."

I will not allow my seller to pay for the consequences of an inspector gone rogue who reported a beyond life expectancy ROOF/HVAC as a defect. 

Seller will respond with "highest and best" and allow their buyer agent to decode to message for the optimistic buyer.

Of course, the dialog is entirely different based on strategy, anticipated buyer response, and the purchase price offered. This concession may be built into the strategy.

Age of systems and roof are items disclosed in NC and SC on the property disclosure form so buyers know this prior to making an offer.... so unless they are not functioning for their intended purpose, post inspection nothing a buyer can do. What's to repair if system is functioning?

Repairs aren't necessary but acknowledging that the useful life is reaching its maximum can more easily be accomplished with a negotiated credit. A cash strapped buyer won't have many options if anything catastrophic happens to discontinue its service.  

If it is functioning there is no problem.  If it is not functioning propertly we ask it to be repaired.

David - I am with Spirit Messingham on this one. I don't see buyers asking for major systems to be repaired (nothing to repair if it is working), and sellers will not typically pay to replace anything that is still working, even though it may be older and near its life expectancy.

I would recommend to any buyer that they have the seller pay for a home warranty plan.

Yes, I have buyers who would be asked to be credited for a furnace, roof or appliance which is near or surpassed (but is still working) its end of life expectancy. 

David Barr - that is true for MA also - it's either working or not working. The inspector says, it's at the end of the life so sometimes buyers ask for servicing - can't ask for replacement to best of my knowledge. Not in seller's market for sure.

Perhaps 5% because most buyers understand if it is working, then it is not defective.