I've been using the Peavey bag for a couple years now, and its held up pretty good. Lots of pockets. (Reminds me when someone asked John Hartford why he wore two vests - "More pockets"). Perfect fit for an accordion even though that's not what they designed it for. I'd be hesitant to take it on a plane. As carry on, might not fit in some overheads or under the seat.
Steve

I bought one from Larry Miller in Iaota for $35. It is the smallest softbag that I've seen in size. It does an okay job but the padding is only about 1 inch think. It's okay to carry around including on the airplane, but I would definitely NOT check it in with my luggage. I really like the Peavy available at Savoy, which I believe is $75.
Maz

My PEAVEY bag cost 75 dollars about a year ago from Savoy's. It's a great bag. Marc also has so nice padded accordion straps for 15 dollars.

If money IS an object and you are looking for a soft case and don't want to pay $75.

Go to your local Wallgrees, Rite-aid, Piggy-wiggly, and look at the soft side ice chests. They have some very nice ones ranging from $5-15

I have been traveling everywhere, Carry-on etc with a $9.99 version that is finally wearing out after 10 years!

Be sure to bring your accordion in the store to "fit" it. (Don't worry about the funny looks :)

Everyone knows they don't sell accordions at Rite-Aid!

Good luck,
DP

P.S. Added bonus, it keeps your accordion cool in the summer and warm in the winter.

At some Wal-Marts you may find some soft coolers by Ozark Trail with an extending handle and wheels plus pockets for mic cords straps etc. Approx $35. Perfect for traveling. Use um myself!!.