I got myself a 2nd hand Bayan for 200$, made good progress quite quickly (I am a professional pianist), but I am middle aged, and find the instrument a bit heavy to carry / operate (and yet it's a small one, only 3 rows, but still 20lbs).
The repertoire I am after is French musette - Russian/Jewish folk - Paso doble / Tango, and I love Irish music as well. I can play all of these on the piano so it's just a question of practice to get the same on the Bayan.
I am still tempted to get a lighter instrument, like a bandoneon or a button accordion, but I have no idea how versatile these instruments are. I have no real issue of budget, I am just more concerned about not investing time learning the fingering for a given instrument if it's not going to lead to anything.
An alternative is to get a MIDI accordion - would these actually be lighter than an acoustic one?
What are the pros and cons of these various choices (very superficially)?
How hard is it to switch between the various instruments? (going from the piano to the Bayan was faster than I expected, but it's still a massive and tiring mental adjustment, and it can be frustrating to not be able to do on one instrument what flows so easily on another one).