I certainly can see an advantage on using 220. For example in travel, having film occupy less space. I've long been looking and thinking into the 6x9 Fujis and for a long trip and a not too big backpack it seems quite useful. However, as you say, NOT cheap! Perhaps it's better to ship some forward to the places one is going to.
Wasn't 220 just the same 120 film base but without the backing paper except leader and trail? I think part of this markup is due to the specifity of these components. One of the arguments that work against 220 for Ilford is that the backing paper was quite special. Another was that due the small market, the minimum they could order would last them about 2-3 decades at their estimated sales rate. Ilford did their math and it was quite more than 2x120, that's why it's not an endeavor they are getting into. IIRC they still have the broken machine. This is what I've gathered reading around here.
If PE or Simon pop in they will have a closer knowledge.