“All right, so much for that one.”
You're on a dating site. You've been writing text messages with a girl who you matched with, but after a few messages she stopped writing you back. Now you're removing her from your list.
All right, so much for that one.
"So much for ___" is something that you say when you're giving up. You've realized that you won't be able to do what you wanted to do. The most common use of "So much for ___" is this:
So much for that idea!
You say "So much for that idea" when you're trying to solve a problem, and you've tried one solution to the problem but it didn't work.
The other way that "So much for ___" works is by adding a gerund afterward:
It's already ten thirty? So much for getting an early start!
Oh no! He saw us? So much for keeping it a surprise.
This is an expression that people use near the end of a conversation. For example, if you're visiting someone and you think that it's time for you to leave, you can say:
All right, well I guess I should be going.
"All right" can be said in response to something that another person says. For example:
But you can also say "all right" on its own to show that you're ready to end the conversation, even if no one else has said anything.