Don't know if you are still looking but....
I have a Stagi 30 button Anglo G/D Concertina. It is almost 2 years old. I don't use it! I'm not catching on to the push/pull different notes of the Anglo concertina and now haven't picked it up in a few months. It's in great shape as I never used it outside my house and not that often.
I play other instruments and am ready to unload it. Maybe try an English before I abandon concertina all together.
I paid $600-635 (don't remember exactly) new from Elderly Instruments. Without seeing it they said they would probably only give me $200-250 for it and sell it for $300-350, depending on condition.
There's nothing wrong with it. Comes with a hard case too.
I have pictures I'll email if you are is interested.
I'd like to get $325 but will negotiate!!