[brickwall99]

The fiio E3 and E5 might be worth getting, but I've read over time they can start causing hissing.
I'm trying to spend no more than $20-$30 on it.

The reason I'm looking for an amp is that I've heard the HD-201 are not very easy to drive.

I'm mainly going to use the headphones for listening to music from my phone, and watching video clips online, both while at work.

 

[candy287]

with your price range the best you can do is look for a use s PA2V2 AMP by Gary in the for sale section.