No it does not have to be USB it can be plugged into the wall.

Is it possible to buy anything that will make a profit for $250 or would i need to pay alot more.

Hi guys so i have always wanted to get into bitcoin mining but never had the money to invest or wanted to put my computer through the strain. I have recently got my hands on a raspberry pi for free and now that im working im thinking of setting up a USB miner hub. Now i am aware that i will probably not make a profit for a long time if ever but its something i want to do a side project. But i was wondering what do you guys think would be a good USB miner to buy first.

So fare i have been looking at YELLOWJACKET - 2GH+ USB STICK MINER and the HEX•FURY - 11GH+ USB STICK MINER. I was thinking of getting a couple of yellow jackets or just the one hex fury. What do you guys thinking would be the best investment and are there better options or should i just spend the money on buying a miner as it will be costing me around $250 AUD all up if i go for the hex fury.

Just so you guys know what im looking in to making i came across this guide and i like the look of how it is setup so ill be making something like this.
https://learn.adafruit.com/piminer-raspberry-pi-bitcoin-miner


Thanks for the help and information.