Cut & Balayage

So I haven’t cut or done anything with my hair in about 2 years. It’s almost down to my butt and I plan to cut the 4-5 inches off that are dead and unhealthy. Maybe more when I go in to the salon. I have been looking at dying it or getting high lights since becoming pregnant, my hair has just looked dull and mousy. Would it be worth paying the $120-$175 for the cut and Balayage? Has anyone ever gotten one? I’m due in about 11 weeks. Just wondering if I can even dye my hair at all. Any input is appreciated. Also what would I tip them? 20%? 25%?