Yes it is rape.
As fatdoggy said, HK is a very good indication of how much they should really cost.
Consider also that those tires have been shipped from Europe to HK which is even farther away than the US, so the import/tax/shipping bullshit does not fly.
I know that I buy my tires from my sponsor for 8.99 a pair and that's pretty much dealer pricing, so if you shop sells foam for 17-19 Dollars, like most do, he IS really raping you.
Especially a consumable like tires should not have a profit margin of 100%
If you look at places like
www.westcoasthobbies.com , they are selling foams MUCH cheaper and still make profit off them.....