While this sells for $150 (not quite the $100 limit you asked for), it's a classic, simple watch with a timeless design, good lines and reliable.

Here's some of the technical specs:
Titanium Tank Watch Blue Dial Features: Hypo Allergenic nickel safe.
Water Resistant up to 3 ATM.
Limited Lifetime Warranty.
Super Hardened Crystals.
Fold over clasp with safety.
Band width:26 millimeters. (via Madison Avenue Mall)