you should buy a XFX 7770 and this is the best card within your budget i thinkhttp://www.newegg.com/Product/Product.aspx?Item=N82E16814150598
give us your detailed specs like resolution, then we can give you more options.
except he doesnt live in north america so cant buy from newegg. But yea a radeon 7770 would be a good choice, even though its over your budget. You can probably play battlefield on medium settings. If you don't want to spend that much, try a radeon 7750. But with a 7750, you could only play on low settings smoothly.