Brake Flaring Tool....Best to Buy???

I would just get one from harbor freight if you're only going to use it every now and then. Make sure it's a double flaring tool. No need to spend a hundred bucks on one if you're not using it professionally.
I would rent or borrow one. I bought a fuel pressure test kit from HF because I needed it once. What a piece of crap. I should have taken it back but I tossed it away.