what factors you consider when buying mp4/mp3 players??  

nowadays there are a lot of imitation mp4/mp4 from china & hong kong.they are imitation of ipod nano.but usually buyers are being cheated especially for 4GB MP4 player which is actually hacked memory.a lot of buyers being cheated in ebay.it turn out to be just either 1GB or 2GB instead of 4GB.some players have a battery that just stand for a short period before its dead.this products claimed to have better functions than ipod nano like FM radio & picture browser.so i am wondering what quality you determines before buying a MP4 player??is it the brand,price or the quality??which want you would go??