GTAV minimum requirements are Q6600 for cpu and GT9800 for graphics.
https://support.rockstargames.com/hc/en-us/articles/203428177-Grand-Theft-Auto-V-PC-System-Specs
Recommended is I5-3470@3.2 and GTX660 for graphics.
My suggestion is to buy a G4600 4 thread @ 3.6 for about $87.
GTAV is largely single threaded so you should do better than recommended cpu.
Use the integrated HD630 graphics and see how you do.
It is stronger than the minimum 9800GT and nearer to the GTX660.
If you later decide you need stronger graphics, a GTX1050 @ $100 or so is an upgrade option.
For a motherboard, look for a H110 based motherboard with the assurance that it has a current bios sufficient to run kaby lake 7th gen processors. That is the cheapest around $40.
If you need assurance of G4600 support, look for a B250 based motherboard which will be in the $55 range.
Buy a 2 x 4gb kit of DDR4 ram. About $62. A two stick kit will perform integrated graphics better.
When all is done, you will have a basic pc that can be upgraded in the future.
About $200 gets you started.