Obviously price will be the biggest factor to move a SFH but there is more that than just a number. Have you over or under improved the property based on the comps and immediate area? You may have put in granite counters when the other homes have laminate which makes yours more expensive but not desirable for the area. The reverse is also true if you have under improved the property. So before you start dropping the list price, see what the comps LOOK LIKE and ask yourself if yours is in the same ballpark. The last few properties we have put on the market went under contract in under a week with multiple offers but they were priced right, were inline with the area but were done with quality and were in desirable areas.
Unless you are dealing in a low-end market, a home warranty should be a standard inclusion especially for first time home buyers. I also feel we have done a 5 star job but if something fails, I would rather have a warranty in place for the owners . . believe in karma. If the profit margin is tight and $500 makes a difference, see if you can save $$$ elsewhere.
Interest rate buydown or seller assist is common place thanks to the jump in interest rates. We have only had two offers recently that were not looking at seller assist and in a few cases, they wanted / needed 6%. The only way we can support that is to adjust the selling price to compensate to some degree - spreadsheets are great in seeing what is needed to make us and them happy.
Hope this helps . .