A sampling of ticket prices on the Celtics' Ticketmaster site taken Thursday night versus the prices in the same areas Friday afternoon reflected increases of 15 to 25 percent.
"We dynamically price individual tickets based on demand and adjustments are made daily and weekly throughout the season," said Shawn Sullivan, the team's chief marketing officer.
Ticket-broker Jeff McGuinness of Indianapolis-based 317 Tickets bought tickets Thursday night anticipating that they might go up for Rondo's return.
"If I were in the Celtics' position, I'd probably do the same thing," McGuinness said. "They need to capitalize on opportunities when they present themselves. Dynamic pricing is here to stay."
For years, teams used variable pricing, where the prices of games would be dependent on the quality of the opponent, but as the secondary market got more robust, dynamic pricing -- where teams change the prices constantly based on a variety of market factors -- has become more prevalent.
One market factor? A chance to see a familiar player playing for the other team.