People seem to be assessing the worthiness of the cost of this extension based on what they have already paid out for other extensions, some of which might contain some of the functionality of the Forms Toolkit. That value is going to be subjective to each member.
What I see is a collection of form utilities that has been repeatedly asked for in the forum (datepicker, captcha, validations without bloated form code) in a useful package.
I don't use FB (because of the code) but build my own forms to fit my designs, so this extension would be one of the first I would buy if I were starting out from scratch. I bought it anyway because it is a great (and lean) tool and It means I can finally ditch 'Forms 2 Go' and keep evrything WA.
A lot of people have just got what they have been asking for. Whatever cash you may have laid out prior to this release is incidental in this respect.