Snowbeast

So with B/C melodeon the same buttons are generally used for 95% of Irish music, is it the same with concertina as well? I know the concertina has a few notes that are the same but with different buttons, but do Irish players usually stick to certain buttons more than others or does it depend on the tune? Could someone tell me which buttons are mostly used, I assume its the ones in the D and G scales? Also does the concertina have patterns like the melodeon does, like the way the b/c has three on the pull and three in a triangle shape on the push and that's basically all the buttons you need? This video shows what I am talking about. Hopefully this jumble of words makes sense.

I'm in the US unfortunately, you'd think with Canada so close that it would be easier to find D melodeons for Quebecoise music.

I am looking for a one row melodeon in the key of D. Does anyone have one they want to sell or know if there is an online store that has them?

So I actually have the Rochelle 2, would a minstrel be a significant step up? Would it be something I could possibly play for a few year or should I wait(a year or so to save up) and get a clover or ceili when I can?

So I have a Rochelle and would like to upgrade. What do you recommend as a step up? My budget is around $1,500. Should I wait until I find a good deal or is there something in that area worth getting new?