The Jays have three starting to elite caliber catchers. They are going to be severely hard pressed to go into next season with all of them on their roster. Thus, they will have to trade one of them, and Jansen is the most likely candidate as he has the least amount of club control
Also, you should look at this site, which provides you with a rough estimate of a player's trade value. It is known to be used by major league executives in at least some capacity. You will notice that Jansen has median value of 17.8. In comparison, Houser's median value is 6.1., or less than half of Jansen's. Even a prospect like Joey Wiemer doesn't get you all the way there on his own. So, yes, while it wouldn't cost a Chourio or a Frelick, it will definitely cost one of our upper-tier prospects to acquire Jansen.
https://www.baseballtradevalues.com/