You get a home inspection and there are items in need of repair or replacement. But how do you estimate what it will cost for credit back from the seller, or out of pocket?
First, do a Web Search just to get basic numbers in mind. Second, call contractors, electricians, plumbers, or special technicians and ask for a ballpark estimates. Trade professional know best the current costs due to market demand, location, replacement parts, etcetera. Call on a different day and you may get a different price! Third, think about the importance of a warranty. A handyman with no official licenses can offer cheap work--but is it worth the risk? It probably depends on the importance of the repair
Keep in mind all cost estimates are possibilities. Often delays, surprises, weather, or other unknowns increase prices; so plan accordingly.
I wrote up a spreadsheet with all the low, medium, and high costs of typical repairs. And now you have access to it too:
https://docs.google.com/spreadsheets/d/1MJSnzdXy7BVEK1ZpL5Vk0nenjs0-a6L5OVveJPwOpcQ/edit?usp=sharing
I'll be updating this list as time goes on. Check back to see more items.