Unfortunately, I'm in South Africa, where grow equipment isn't so cheap, and I've already spent more than I wanted to. I'm intent on finishing this, but I can't see it being cheaper scrapping my current ballast and buying a magnetic one.
I started with an initial budget as well and went way over!! lol. The best thing to do is budget everything you need for a successful grow, and then double it. You will always end up spending more because you will either find new things, or find out that something you thought would work wont work, etc. Good luck man! you will get it sorted