Plus there are a few more variables in addition to budget, such as do you want a pre-built machine or to do it yourself? Desktop or laptop? What kind of games?
I upgraded my friends pc a few months ago for just under $3k* so he could play and stream things like Elite Dangerous, Destiny 2 etc so I could make some suggestions based on that, but yeah it's a difficult question to answer without more information.

*this would have cost maybe $1k more if he didnt already have a case, power supply, monitor etc and more again if it had to be bought from a pc builder/shop so that's also something to take into consideration