How much should i sell my pc for?

I am guessing desktop and realistically. 350 without monitor and keyboard and mouse. 400 with all that stuff.

Does it have a legit Windows license w/key? Is it a self built or off the shelf from a major manufacturer? If self built, what quality of components? Where do you live? That all comes into play. The best way is to check local used sales ads and see the average rates for similar systems.