Its a combination of both if you want, you can send me a list with your pc's specs and i will take a look to what you can improve at a low cost
yubibotter helped me build this like 1-2 weeks ago its good but thought how i can improve it its a i5 3570k i believe, 16 gb ram, asus gtx 680 gpu
only thing i can really think to improve is maybe i5 to i7 but that setup is solid, you should be able to run 3-5 clients on that. Also depends if its osrs or rs3 - rs3 takes more resources