I think there is another factor here that no one is addressing.
It could well be that the purchase price of the units is only one small part of the total equation. We have heard that they are planning to sell designs in the catalog and pre-qualified materials. Perhaps the long term plan is for those activities to account for a significant source of revenue, and eliminate the need to charge for basic access.
I can only imagine that the Glowforge team is hard at work figuring out additional ways to make money from service offerings. Hopefully those won’t include going back on their word.