i believe Narragansett still makes some of the more affordable plain bridle leather belts. killer for US based makers is the USPS shipping.
ETSY should also have plenty of people selling belts made of bridle or other good leathers.
for work + play, 1 to 1.25 inch width with simple buckles should be fine. with
sizing wise usually they punch the middle hole to your spec, so measure yourself instead of using your pant's vanity size.
Equus is also well regarded for their quality options. pricier but should be within your budget
main downside with buying online is buying coloured belts to match your coloured formal shoes. uncalibrated photos + uncalibrated monitor = not accurate reflection of the colour.
'Natural' colour belts not so much, since the colour is expected to evolve as you use and feed it with oil/wax conditioners