lol no. Would never work unless every country implemented. Your largest earners aren't going to purchase a single domestic product or service. Even medium earners who are smart won't. Comparing a tiny VAT to a 25% country wide sales tax is extremely Fake Sugar Dick (WARNING, NOT THE REAL SUGAR DICK!).
It wouldn't just be an issue of inter-country competition. A 23% sales tax would instantly make everything 15% more expensive. That 15% would create a black market for just about every good and service imaginable. You wouldn't have to be rich to take advantage of that market. Anyone who says such a system would be revenue neutral is a huge and complete dumbass.
The goods and services we buy now already have tons of taxes included in the price. Corporate taxes, sales taxes at various stages of production, etc. are all rolled into the final price we pay. The fairtax eliminates all such taxes and imposes one sales tax that applies only to final retail sales (so, it's not like a VAT, that applies to all levels of production). So, in theory, the fairtax would reduce the price of goods and services, at least somewhat offsetting the new sales tax.
The black market issue is a valid concern, and that's one reason why the IRS couldn't be disbanded completely. Somebody has to make sure people aren't setting up sham businesses to purchase goods wholesale (not subject to tax) and then sell them on black market. And I suppose it's possible people will try carting crap over from Mexico, which is another reason for tighter border enforcement. I believe Canada already has a VAT, so I doubt any money would be saved by buying stuff there.
Yes, the people who put money in Roths will probably lose most of the benefit of that savings vehicle, but there's going to be winners and losers in any type of reform.
The poor do not get screwed, because of the rebate system. This rebate system would actually ensure that they pay zero federal taxes up to the poverty line. (Well, I guess if you're poor and the federal government is actually paying you in the form of tax credits, etc., then you're getting screwed a little, but you deserve it).
One concern I have is how the fairtax would actually be implemented. The transition seems like it would be a nightmare. First, you've got to repeal the 16th Amendment. Then, you're going to have massive runs on goods and services right before the fairtax goes into effect. Has that been addressed?