Buying a home - Need fast advice about open grounds

Hey gang, I'm a complete novice when it comes to electricity or anything home-related and need some quick advice.

I'm in the middle of purchasing a home that was built in 1986. The inspection revealed several open grounds throughout the property (at least 5 examples were provided). I asked the seller to eliminate all open grounds but he refused and offered me $1,500 credit instead. I understand that GFCI outlets can be used as a bandaid solution for this, but I'm worried that there could be bigger issues with the electrical system due to its age that pose a risk of fire or damaging electronics.

I work from home and I'm also a music producer with multiple laptops, synths, speakers, and turntables constantly plugged in, so protecting my electronics is of upmost importance. Is it reasonable for me to ask the seller to at least correct the grounds in the studio room? Am I being overly concerned about this? Would it make more sense to ask him to install GFCI's where necessary, and I can slowly eliminate the open grounds over time? I'm concerned that system is a big mess behind the walls and will be overly costly to fix.

I appreciate your insights!