yea he/she could go with a 60 dollar card and 30 for a new case and 30 for a new psu and it would be optimal for the cpu he/she has but i would just put the money towards a new build imo
if you really want to upgrade what you already have go with something like this
PCPartPicker part list:
http://pcpartpicker.com/p/3d4AA
Price breakdown by merchant: http://pcpartpicker.com/p/3d4AA/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3d4AA/benchmarks/
Video Card: Sapphire Radeon HD 6570 2GB Video Card ($59.99 @ Newegg)
Case: Xigmatek Recon ATX Mid Tower Case ($29.99 @ Newegg)
Power Supply: Antec 450W ATX Power Supply ($29.99 @ Newegg)
Total: $119.97
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-03-20 02:56 EDT-0400)
but if it were my money i would put it toward a build for around 600 dollars