Budget amp and dac?

I recently bought the superlux hd668b used for 15$ to replace my broken razer electras,and with the money I saved I want to buy a amp/dac for less that 100$.You may be thinking that buying a amp/dac would not be necessary for these headphones,but I will in a year or two buy more expensive headphones since I would be able to save more money.Right now I'm looking at the fiio e10 or the creative sound blaster x-fi hd,and I was wondering which of these two would a better option to go with.Also I would like to hear if you guys have any other recommendations because I really do not know shit about audio I just go by with what the reviews say.

Buy some better cans first, don't worry about amps and dacs until you actually have a use for them.