Answer
Start by comparing the option against the practical details that will affect the experience, not just the headline price or a few attractive photographs. For bookshops and reading resources, confirm languages, current stock, maps, children's books, local-history material, ordering, opening hours, payment and whether a library, hotel exchange shelf or trip to a larger centre is more practical.
Khao Lak has fewer specialist bookshops than Phuket or larger Thai cities, so hotel book exchanges, community groups and advance ordering may be useful.
Ask for the important points in writing before paying or making a firm plan, especially anything involving availability, safety, deposits, inclusions or cancellation. Current operating details can change with the season, weather and staffing.
A reliable provider or organiser should be willing to explain what is included, what is not included and who will take responsibility if plans change.