I recently received a little adjustable power supply, purchased off ebay for dirt cheap.  It’s pretty nice, so if you’ve been considering something similar have a gander at the video:

It can take between 4.5 and 23V in (recommended to stay below 20V) and has a 1.5V drop-out.  It’s claimed that it can source up to 2A continuous (with 3A surges)… I dunno, don’t usually use some much current anyway.

The PCB and LCD screen both show it to be a “Winners” brand, but searching for same on ebay doesn’t generate much love.  Doing a search on ebay for “adjustable step-down dc power supply” seems to work better, and it looks like banggood is selling the same module for the same price (though I find their shipping horrendously slow).

Enjoy.