LISP IDEs: CUSP rules

I saw the prices for Allegro Common Lisp and Lispworks. 600 and 2000 bucks, respectively, per user.

I get a

"java.lang.NullPointerException"

whenever I try to load the REPL. Any suggestions?

IMHO, so much nicer than emacs + SLIME. but really I never liked emacs. (no flame intended).