Did my favorite search query, and the result were pretty bad, as expected:

"robotics servo motors with two-directional control for under $100"

1. https://mjbots.com/ - their motor are $1369. FAIL.

2. https://www.pololu.com/ - this is huge store, but they do have some motors like that. Pass, but wish it linked to specific page and not top top-level one.

3. dh-robotics.com - no prices, but some products on open market are few K$. Likely fail as well.

4. https://www.robotarticulation.com/ - The product is not for sale (early beta), and it looks likely much more than $1K. FAIL.

5. https://www.lynxmotion.com/ - another huge store, most two-directional motors are expensive but there are some under $100... Pass, but wish it linked to specific page and not top top-level one.