I'm not sure about price conversions and GPU prices in rs.. But if you're not going for high resolutions or high settings for new games i'd suggest a GT620.
It's what I started on when I first got a PC from my parents (for homework and 'light gaming') and it manages to run games ok.
(Well, it did about 9months ago.. and I wasn't running BF4 etc, just older games from 2011 and back. EG Fallout3, Oblivion etc)
But it will be good enough to do basic gaming and your design software! I've managed to find a "Gainward nVidia Geforce GTX 620 2GB DDR3 Graphics Card" going for 3699rs on eBay..
Otherwise, you'd be better off getting advice from someone who's been following Graphics Card prices for longer than I have.. It may not be the best power for money option! :/