BYU is great because the tuition is nice and low, so government financial aid will cover most of tuition. Also, there are some good scholarships available. I was able to get plenty of funding the whole time I was here. Check with your department/college to see what scholarships there are available. I actually applied for one, and I didn't get it, but someone on the selection committee noticed that I was from California and directed me to a different scholarship based on that, which I was awarded. So there's more options than you think, and you could probably talk to your adviser about it.