So what kind of stuff have you been tying?
This is a good article on different vise designs:
Fly Fishing Gear, Fly Tying Vises - MidCurrent
And this is a review from 2006 of different vises:
Selecting the best fly-tying vise, by Hans Weilenmann and Bruce Salzburg
For under 100, you could go with the Danvise lists for 80 but you can find it for 65 if you shop around. It's a "true rotary" vise, and a very good value if you are interested in rotary tying techniques (spinning the jaws to wrap thread etc). You can also tie on "true rotaries" the conventional way, by wrapping material by hand. It comes with a DVD to show you how to set it up and use it. I think it only comes as a c-clamp, with base extra. The stem is an odd size (metric), so you have to get a special base to fit it.
Also under 100, you might want to take a look at the HMH Silhouette. It retails for arounf 90, but you can also find it for less. It's a "360 rotary" that lets you spin the jaws to view the fly from all sides, but because the hook shank doesn't rotate in a constant plane, you can't tie using "rotary tying" techniques. It is an excellent, basic vise, with excellent jaws, and the rotary feature is nice feature to have. It holds hooks from the 20's up to 2/0. This model doesn't allow changing jaws if you need to tie larger.
The Peak is also an excellent vise, retails for 150, but again you can find it for less. At 127 that would be an excellent price. It is also a "true rotary" vise. It holds hooks from 20's to size 2 with the standard jaws and SW jaws are available for bigger hooks.
There are lots of other choices, but I think either one of those 3 would be great for you.