As far as I know, HL2RP does not have functionality to purchase tokens separately from a package such as VIP or Gold, so the simple answer to your question is "No."
However, that being said, it's up to Roflwaffle whether you can actually do it or not, he or another one of the administrators with power over HL2RP may be able to say whether or not you can, but speaking strictly from the current infrastructure in place, you can't.