Yes. eSIMAdvice currently lists 9 AlpineSIM Belize plans.
The lowest displayed AlpineSIM Belize plan is Belize · 500 MB · 1 day · 4G, at $6.17.
Belize · 20 GB · 30 days · 4G is the current best-value match by displayed price per GB: $7.19/GB ($143.84 in total).
Yes. Eligible displayed prices already include the active AFFINCO coupon where the provider rule applies.