Is this unethical? Tacky? Ill-advised? Am I selling myself based on
future value that I know they will not receive and am therefore
committing a type of fraud?
No, it's not unethical, tacky, or ill-advised. And it's certainly not fraud.
Whenever you are in a performance review, it's a good time to seek a raise. In many shops, an annual raise is pretty much automatic anyway.
And while you are planning to move "in about half a year", you don't know what will actually happen that far off.
You might decide not to move. You might decide to move sometime further in the future. You might even decide to move and see if you can continue working for your current employer (in a different division, or perhaps even remotely).
I believe everyone should see if they can get a raise every time they are having their performance reviewed, unless they have already publicly announced their departure. To me, this is just good business.
It's important to get your current salary as high as you can if you are planning to seek new employment. Employers often base their offer on your most recent salary. Having a higher starting point adds up over the years.