About registrations and standby testing

<p>Hi, I have a question. According to collegeboard, the only test center in my country is full, so I'd have to get a visa and go to an other country to take it. But the thing is this. Apparently, collegeboard counts both the sat i and sat ii in one category, until the limit is reached. When I called in this test center, I was told that almost always the number of test takers of sat ii (which I want to take) is very small, so I'll probably have a chance to get in as a standby.
The question is the following: If I register on collegeboard in an other test center, and I show up at the test center in my country, assumming that there is space so that I get received, how much would I have to pay? Will my registration for an other test center be considered valid, so I'd only have to pay as a test center change (21 $) or would I as a standby, have to pay for a whole new registration + the standby fee? (I have to wait until the deadline for registration passes so I know if there will be enough place for me as a standby, because the test centers only gets the information after registration deadline :(( )
Could someone please answer fast, as the deadline is tommorow?</p>