what is DESKTOP-9MRBASM worth?

That is the "Device Name" windows assigned to your computer when it was first installed and tells us nothing.

try adding some of the specs. (ie... cpu, gpu, ram, drives, etc)

no brand: ==>  no idea from us.

That really depends on what YOU mean by "DESKTOP-9MRBASM".  Google can find absolutely nothing to do with it.

a mcdonalds big mac and a pat on the back

100.00 at most maybe less