Meaning of まえば in Japanese

息子の前歯が曲がってはえてきました。
My son's front teeth have come in crooked.

前払いしてほしいですか。
Do you want me to pay in advance?

「騙された」と言ってしまえばそれまでですが、「うまい話」に乗った当人であることは間違いありません。
If you say "I was tricked," well that's certainly so but there's no mistaking that you were the one who signed up on a "sweet deal".