No button for my domain account as well. Have billing enabled. And when I attempt to send feedback on this issue, I get a "submission failed" error!

Have used micro instances in the past as remote development and deployment environments and a micro instance and it works ok. Wondering if something in between micro (0.7G) and standard (3.5G) might be better considering devenv can get pretty beefed up using certain modern frameworks we won't mention by name ;)