I think people with longer blunt-cut hair can get away with cheap haircuts much easier, but I have never been happy with the few experiences I had with those places. My hair type and texture can be challenging to cut in a shape that grows out well. A bad haircut on me means that the waves hit in weird places, stick out, and put bulk where it's not needed. Thick, straight hair like yours is much more predictable.
Your hair always looks nice and sleek, so there is not a drastic difference in appearance between the two approaches. Still, I do like the layers, and I think they add a little extra sophistication to your look. I like 5-6 in particular. How does it feel to you? Do you feel better after a Supercuts cut or a salon experience?
For me, it's worth the extra money to relax in a nice salon six times a year, flip through fashion mags, chat with my stylist (who I have been going to for 10 years), and most importantly, walk out feeling fab with something a little different each time that I love. Budget wise, so I buy one less jacket or something a year -- that's fine! I think you need to decide whether its worth it to you.