I think that the developer must reconsider this price as someone who only wants to get the comments system (and no other component of yours) cant have it.
Thanks for the review, glad you liked it. Actually, the price is not component specific and its the price for the Extension club membership, with which one gets access to all premium extensions presently offered and coming up. Pricing individual extensions might prove more costly to users wishing to use more than one extension for their Joomla! sites.