That would be an interesting exercise, as there would seem to be many valid methods for calculating this.

I would think that the most lucrative method would be calculating the cost of obtaining/maintaining Diamond status. Assuming an average room rate of $200/night, the value of this benefit for this year would be the $200 multiplied by the lowest of number of stays/nights required to renew Diamond membership (possibly nothing for people that have already renewed), followed by $5000 (25 stays * 200/night) for every year thereafter where the Gold Passport member remains a Hyatt credit card holder.

I don't think that there would be a point equivalent that Hyatt could offer, as no amount of points could grant the cardholder Diamond status, nor impart on the cardholder the benefits of Diamond status.