Yes. eSIMAdvice currently lists 51 AdventureSIMs Bulgaria plans.
The lowest displayed AdventureSIMs Bulgaria plan is Bulgaria · 1 GB · 7 days · 4G, at $1.10.
Bulgaria · 50 GB · 30 days · 4G is the current best-value match by displayed price per GB: $0.48/GB ($23.85 in total).
Yes. Eligible displayed prices already include the active ESIMADVICE coupon where the provider rule applies.