Translation:Let's meet in a bit.
Confer here. I realise of course that 있다가 also has other meanings which reflect the 있- + -다가 combination more transparently (i.e. "after being" or "after -ing"), but if you ask me, “in a bit” is still a fairly obvious extension of “after staying [somewhere for a while]” (similar to 갔다 올게, which I would also translate freely as “I’ll be back in a bit” even though it’s literally “I’ll go and then come”). So I was wondering if the phonetic spelling 이따(가) was still considered slang (similar to how some people often write ㅅ instead of ㅆ in the 받침 on the internet). But if the 이따가 is an officially accepted spelling, then please forget I objected ;)
Interesting, I never thought about it like that. I asked my Korean friend and she said they're not related, but I see how one can find them similar in meaning. It seems though that they are used differently in terms of grammar (since 있다가 will be in the verb's location and 이따가 can be more liberally placed in the sentence). Hmmmmmm