I started out playing a Jackie, a 30 button English beginner's instrument. I bought it on eBay for about £80 and it did me very well until recently. The buttons are laid out exactly as the 48 button ones, but with fewer notes. However, it was well in tune, if a bit heavier in the hand. I believe they retail new for about £300. I have now bought a Lachenal, but at least I was able to see if I could get on with the instrument without paying a fortune.
jmmo