Fellow Naturalista here.
I spend $0 on salon visits. I haven't been to a salon since July 2012, shortly after I decided to transition to natural hair. The only money I spend is on hair products. I've found what works for me and try to buy them on sale.
As for styling, I'm very low maintenance. I usually wear a wash-and-go and leave it alone for 1.5-2 weeks. Occasionally I'll wear a twist out, and even more rarely, I'll straighten it. I'd caution you against straightening your hair too much, as it can take a long time, and heat damage is a risk.
I don't know how long your hair is, but you may be able to get away with only doing a few twists. I only put 4 chunky twists in my hair after washing and then I'll unravel and them in the morning. My hair is still slightly damp, so smoothing my hair leaves me with a stretched wash and go.