You absolutely have to have limits in terms of how much you give people in a relationship. Unless they are as dialed in as you are and giving 110% (which, let's be honest here, tends to only occur in a really good marriage), overextending yourself doesn't serve your best interests.
I receive a lot of questions from people who ask me the following:
"When should I pay for a date?"
"Should I pay for the entire trip (even though I'm a bit resentful about it)?"
"When can I go all out and do flowers, candy, balloons and teddy bears?"