I'll vouch for two of the three listed vendors (EWA and FastOne) and add another:
http://www.gpmini.qc.ca/
Their site is up but most of the inventory sections aren't there yet. I e-mailed them about two Minichamps CLK-DTMs I wanted and they had both for a good price. Also, they're in Canada (Quebec) so it avoids any possible duty for me.
$24 is a good price for a new Minichamps 1:43. I got my BMW M1 BASF for about $25.
Others (like the Ferrari F355s and F50s) can sell for $50-$100, although I got an F355 Spider for $30 on eBay.
The DTM cars (Audi, Mercedes) usually go for about $50US each.
There are a few others that can fetch $150US+; I have one of these on the way. :giggle
:cheers