I was looking at the Wrapsody semi-stretchy wrap carrier for my coming twins. A babywearing expert suggested that a first time parent shouldn't go with a non-stretchy wrap (it takes practice to use competently) and twins will outgrow a stretchy wrap far too quickly, so the semi-stretchy wrap is a good mix of the two. None of the other options are really all that great for twins, they are either harmful to the baby (hip displasia and suffocation risks) or uncomfortable or too difficult for the parents, and often both.
(By the way, if you're having one baby, check out ring slings, they looked simple and effective to us, but not easy to use with twins. I've never actually tried it, but I've heard good things.)

Here's the one I was looking at:
http://www.wrapsodybaby.com/shop/pro....php?prod=isis
(there are different patterns and colors, but that's the basic idea, plus I'd like to get 2 so my wife and I can both wear them at once and quickly and easily take one or both babies hands-free)

That's kind of expensive for what appears to be just a piece of 2-way stretch fabric that's maybe a little wider in the middle. I was looking online and found plenty of people making their own quilted carriers, which is basically just any long piece of non-stretchy fabric, but I only found one person who actually tried using 2-way stretch material:
http://crunchywannabe.blogspot.com/2...baby-wrap.html
(that last post is me, by the way)

So what I'm asking is whether or not this is practical. Are there any advantages of the $84 (a little cheaper on amazon right now) wrapsody over just buying a piece of 2-way stretch cotton-lycra blend at any fabric store for $5 or $10? If I'm buying the fabric, are there any dyes or chemicals to avoid? Does anybody know how stretch it should be ideally?

Any help would be appreciated. Thanks.