Hello there..
I have a Pioneer VSX-D810s AVR that is without a remote that I will need for speaker/sub set-up. Someone years back was in this same pickle, [Link: remotecentral.com], but that suggested remote replacement is no longer available. I understand finding one that has AMP0013 setup code is what I need, but am having trouble finding which remotes will work with such. And surely, budget is a factor.
Big thanks for any help and your time..

The RCA RCRP05B or the OneForAll URC-8820N will control many functions using setup code Audio 1935. Some other functions are accessible through Audio 1023. For any functions you need that aren't available on the remote, it is possible to program individual buttons. At hifi-remote.com, there is an upgrade file for the VSX-D710s, so we know nearly all the VSX-D810s IR signals.

The RCA is $20 or less at Best Buy, Walgreens, Sears, Frys, etc.

If you get one of these remotes, try it out and report missing functions. We'll tell you how to add them to the remote.

If you are really only interested in basic functions like volume and power, nearly any universal will control this unit, but I suspect you'll want some of the less common functions.