John I think you may have a couple errors..the RA50 is a MT32 map[LA ]and is not like the E70, but the RA90 is like the E70[SC]..the RA30 was released after the RA90 just prior to the RA95..it was designed as a compact , no frills arranger module, and did not sound like "crap"..in fact it is the same exact sound source as the other lower line Roland GS instruments..
They can be found under $100, and make a better choice than a Casio for me[with your favorite controlling keyboard]..