The 233MMX is the last Intel s7 chip for desktops (not counting the 266 laptop cpu). So yes, it does have collection value. Preferably the retail version with glued Intel sink/fan.
If it's for speed, many and many 200s and 166s actually run fine at higher speeds too.
In fact, I've put a 200MMX on a super 7 board (pc chips M577) and ran it at 250MHz (100x2,5) for quite a while. Lots of s7 boards support 75 or 83MHz fsb which makes the 200MMX oc to 225 or 250MHz at stock multiplier, in case the cpu is multiplier locked.
Intel did cripple them down to lower speed ratings due to market demands, but quite a lot could have been rated 233 or higher in the first place.