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.
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.