There's no such thing as a D/G piano accordion - that would be a melodeon.

The easiest to learn to play really depends entirely on what sets your bells ringing. Just feeling like learning an instrument isn't enough, you see. You have to have a burning passion, or it won't happen.

Which instrument do you most like to hear, and feel the most attraction towards? That should be your first choice - not driven by cost...

Always remember that a good quality instrument bought secondhand will usually re-sell for more than you paid for it if you decide it wasn't for you after all.

Personally, I've never ever sold an instrument - they're all my babies, good or bad, and I love 'em all to bits! It's a bit crowded, though...! Sixteen guitars, around ten piano accordions, six concertinas, four mandolins, the list goes on...!!

As I play piano accordion, melodeon, Anglo and English concertinas, and most stringed instruments, too, I can safely say they all have their inherent difficulties - which will be overcome if you have the passion.

The problem with the piano accordion is size - even the smallest is relatively heavy in comparison with a melodeon or concertina. However, for English and Scottish stuff, the piano accordion is probably a good choice, as it is reasonably 'self sufficient' - you can readily play in most keys, and provide your own accompaniment.

You can do the same with more difficulty on an English concertina, or the more expensive 40 key Anglo concertinas.

Simple D/G melodeons are very satisfying to play, and fairly 'instant' results are possible, but they are somewhat limited because of 'missing' notes, restricting the keys in which you can play. A three row, either A/D/G OR B/C/C# will get around that, but they are relatively big and expensive, and certainly not so straightforward - a small piano accordion will do the same job more accessibly.

I'm sorry, but asking for advice as to what to learn to play is a personal preference issue - nobody can give you the advice that is right for you other than your own gut feelings...

Good luck!!