Is (and if so, why) "empirically real" is a purely logical predicate for Kant?

Kant famously illustrates his thesis that existence is not a "real" (i.e., determining) predicate by claiming that there is no difference in concept between existing and non-existing 100 thalers. But existing 100 thalers are, unlike non-existent ones, present to intuition and thus seem to have, in addition to the determinations of the non-existent ones, those of time and space (i.e. "apriori forms of sensibility"). Which is to say that, in Kant's terms, they are "empirically real". Am I getting it right? If so, how, given this, could Kant claim that the predicate of "existence" is a purely logical one?