there will be a price to pay (for something)

1. Literally, there will be a significant financial cost required to do, access, or obtain something. You can customize your PC, but there will be a price to pay for the more top-of-the-line features. A: "Would we be able to add a stopover in Hawaii to our flight home from Japan?" B: "Sure, but there will be a price to pay at this late stage."

2. There are going to be significant negative consequences or repercussions that come as a result of some decision or course of action. I wish people would realize that there'll be a price to pay for all the pollution we're dumping into the environment! You may not care right now about all the junk food you're guzzling down, but there will be a price to pay when you start getting older.