The heavy-duty extra thick drysuit shirts and pants are a very handily alternative to the standard-weight dry suits for people like me that sometimes tend to bump into or scrape things against the dry suits during a dive. They are much more resistant to tears, punctures and other mishaps than the regular products, and are just as easy to repair as the standard products. I think they are really worth the extra expense.
I would also like to mention that the owner of the site can always be counted on to help a customer not familiar with this style of dry suit in natural latex to understand the limitations and proper care of a natural latex dry suit, and he shows a real commitment to helping his customers get the most and the longest useful life from their products.