If earth-friendly materials are a high priority for you when buying jewellery, then Sprout Watches offers budget and eco-conscious options.

This model comes with a fish skin strap (made from harvested, non-endangered fish skin byproducts), a corn resin case, mother of pearl dial, mercury-free battery, and conflict-free diamond markers. All for USD $70. They offer many options for men, women and kids, and work in a number of ecologically conscious materials (like organic cottons for bands).