Definitely! I just snorkeled Melissa's Garden and the nearby Pam wall because that day the boat had too many passengers so diving gear wouldn't fit. Even snorkeling there was fantastic.My opinion is: it's worth considering. Rp 5M = USD $370. Awesome site.
Most of the people visiting only Gam/Kri usually take a day trip to Piaynemo (it's the highlight of Raja Ampat topside). The best that one can do is combine this day trip to Piaynemo with diving Mellisa's garden and Pam wall. This is easily done, but only if few people (up to 4-6) share the boat. More divers than that, and it's getting too heavy for the boat to do the long trip. All these can be arranged by the homestays and the dive operators.