Real estate, for example.
Say you want to buy a newly constructed home (since it's new the tax would apply). It's a $200,000 home, you have 10%, or $20,000 to put down. But-with the tax, you actually now need over $69,000-your down payment plus the tax (this doesn't even figure in closing costs which would probably remain the same). The bank is not going to lend more than the house is worth, so you can't get the house and have to buy an existing "used" home. The construction biz would go belly-up without several years to cushion the blow.
Also-the effect it would have on those that have saved money for years and already paid tax on it having to pay tax again to use it.
I LOVE the national sales tax idea, but these are some concerns I have.
For more information on this go to : http://www.fairtax.org/pdfs/Homebuilders%20will%20benefit%20from%20the%20FairTax.pdf