The reason to expect Starlink to provide lower cost than VSAT is that SpaceX is currently paying less than $500k per functional Starlink sat (including both manufacturing and launch cost), and intends to dramatically reduce the cost from that before launching the larger stages of the constellation. In contrast, the geostationary satellites that are used by VSAT cost near billions per each.

This three orders of magnitude difference in cost can be expected to be reflected in the price of the service.

That’s simply not true. Viasat offers much lower cost per GB. The higher speed plans are less than $1 per GB. The cheapest plan is $50/40GB. That’s already far cheaper than mobile data.

Starlink and others are likely to significantly improve on that, too. Fundamental costs (especially for later versions) are cents per GB or lower, competitive with AWS transit fees.

Touché. Where can I find such offers?

This one: https://www.reviews.org/internet-service/viasat-reviews/

(look for "data cap") ...note that, for instance, the $50/month plan goes up to $70 after 3 months. But the data cap of 40GB is a soft cap.

It is much cheaper than I thought. Thanks!