All above replies are certainly worth looking into.
From what I've seen, there are a few options out there that are pretty readily accessible for a gyuto under $100 using Shirogami. I have personally been on this same path for some time, and found many well-respected knives with both White #1 and #2 for under $100, in some cases under $50. (Please note that I'm no chef, so I usually go for shorter and therefore less expensive patterns, like Santoku and Funayuki). Aogami (Blue) steel, especially the "super" variety, is somewhat more expensive on average, and of course there is yellow paper steel, offered in even cheaper Japanese knives, though in this case you (may) notice a slight dip in performance.
Chef Knives To Go is a great resource, carrying many of the largest brands. If it's popular enough to be on there, I am pretty sure of its quality by that virtue alone.
At CKTG, the Tojiro ITK line is very popular, using White #2 in traditional patterns. There 240mm Gyuto is normally right at $80.
http://www.chefknivestogo.com/toshitk24wa.html
I have also heard great things about Yamashin knives, which use White #1 for the blade steel. By all account these knives are comparable to the Tojiro, with a compound grind (a feature usually found only on higher-end blades) and the added bonus of the slightly harder, more carbon-rich steel. These retail for a bit more than the Tojiros, currently the 240mm is going for just over the $100 mark.
http://www.chefknivestogo.com/yawh1gy24.html
The Richmond Artifex is a great low-end stainless option, and is currently on sale. The finishes on these knives is usually found to be of a higher quality than the others.
http://www.chefknivestogo.com/fufkm24wa.html
For the lower-end Yellow paper steel, Tosa knives were recommended to me by a fellow forum member. They are available at hidatool I believe.