Mmmmmm, just surfing last night and coming accross a few things I started to wonder whether it would be possible to get 3,4-dimethoxy-5-ethoxyphenethylamine from 3,4-dimethoxy-phenethylamine.......Hmmm. (anyone think that this would be likely, or much easier)
Interesting. I wonder how simple it be to get other obscure phenethylamines from DMPEA...

Nope, you would either have to start with vanillin, or the substituent will end up in the 6-position. This has been discussed before - search for "veratrole" and "bromination".