Bill,  I have seen a number of PianoLodeons on eBay, an on-line auction
provider.  They have ranged in price from about $150 to over $300.
There is a dealer in Pennsylvania who reconditions them, and his price
is about $500.

Factors to consider are condition of the plastic case and the condition
of the playing mechanism.  Any problems with the mechanism will cost
you either in time or money to have them repaired.  Problems with the
case are likely to always be there; it's hard to repair the hard
plastic these are made of.

Other factors might include the number of rolls and whether the
instrument comes with its original box (that's a valuable item for
some, but not all, collectors).

This should give you an idea of the range of prices that these
sell for.

Musically yours,

Bill Wineburgh
http://members.aol.com/WWineburgh/musicbox.html