Row 44 claims 81 Mbps downstream; Starling, 10 to 15 Mbps: Neither firm has provided an idea of what it would cost to airlines. Row 44 is starting up with North America coverage via Ku band satellites, the same approach that Boeing used (at maximum speeds a quarter of these) with Connexion for trans-oceanic connections. Wi-Fi isn't yet certified to be used in planes traveling in FAA airspace, so there's that issue to overcome, too. Row 44 plans future entertainment offerings over the high bandwidth service.
Row 44's equipment weighs 150 pounds and requires two days' installation. That means that the appropriate service window must be found. Based on details from Boeing and other firms, I would expect the full cost of installation, including airplane downtime, is $250,000. We'll see if Row 44 provides additional details on cost and pricing. By contrast, AirCell says its air-to-ground gear will weight 100 pounds, and cost about $100,000 and be installable overnight. AirCell has the advantage of installing an antenna under the plane pointing down, too.
Row 44 will be competing head-to-head with AirCell in the western hemisphere, but AirCell's current maximum downstream (and upstream bandwidth) are constrained to about 1.5 Mbps based on their technology choice (a good one) and the spectrum they won at auction.
Starling will also offer Ku-band service using an "ultra-small" antenna to provide the least amount of drag. Drag is equivalent to weight in terms of fuel burn, and thus less drag reduces the cost of operating the service. The service is promised at as fast as 10 to 15 Mbps downstream and up to 1.25 Mbps upstream. On-demand TV and other entertainment offerings would be part of the package. Starling is demonstrating the service this week. The article linked has an incorrect conclusion: it looks like only the FAA would need to approve on-board Wi-Fi, and guidelines from the FAA for airworthiness on satellite links are already promulgated.