Panopset desktop software is currently free, for anyone who can't afford it, and open source, under the GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007 license, slightly modified with two provisions related to the Blackjack module.
If you and/or your business is doing fine, it is $25.00 per year. Proof of payment is the license.
Limited offer: $100.00 for a lifetime license, per user. The first 1,000 who pay for a special permanent license, also get a numbered signed certificate that they'll want to save in case Panopset ever goes public, or is sold.