Yes. eSIMAdvice currently lists 3 Nomad eSIM Cuba plans.
The cheapest Nomad eSIM Cuba plan is Cuba · 1 GB · 7 days · 4G · Local, at $17.85.
Cuba · 5 GB · 30 days · 4G · Local has the lowest price per GB right now: $11.73/GB ($58.65 in total).
Yes. The prices shown already include the ESIMDUDE15 coupon where it applies.