Any recommendations? I'm looking for something at or under $20/month.

cyberservers.net

I have excellent experiences with www.infuseweb.com

Unfortunately, they don't meet your price requirements, however sometimes it's worth paying more for a good service. :)

I have posted to infuseweb.com in order to have smaller reseller plan for something arround $25 per month

also u can check
exa-bytes.com
inetio.com

You can try with reseller2host.com as well