Rick, My concertina is worth about $600.00 new. And are avaible from the "Button Box" it is a Stagi. No mine isn't for sale...Weeeelll for the cost of a good Lachenell, I might consider it.
The Stagi has Accordion reeds in it. So it sounds a bit differant than the english style of Anglo with concertina reeds. However, you can BEND the accordion reeds...(heh heh) ya want blues? Can be done with the cheep Stagi. Go for the 30 button, metal ended one. They seem to have the best voice. However they can be a bit slow for fast Irish stuff.
WARNING! There are some very cheep 20 button boxes out there. They go for about $175 or so. I have one. It is a real piece of crap. You have to spend about 1/4 your time repairing the darn thing. Springs get unbent and won't spring anymore, pads fall off, the Chinese ones are just junk. About the same as the "Hero" accordion. You have to be a Hero to get a tune out of it.
Ignore the nay sayers, they wouldn't know the differance between a concertina and a slinky in a hanky.