The goaltender trade market tends to be underwhelming. While the occasional starting goaltender moves, the price is often quite reasonable. Those deals end up happening because a team is overflowing with NHL talent in the crease or there is an expiring deal to move. Suddenly, there might be trade talks to fill a need.
Consider the trades that have occurred recently for NHL goalies:
Fleury was traded from Vegas to Chicago in the summer for Mikael Hakkarainen, a prospect only by the loosest of definitions. It was a cap dump by the Vegas Golden Knights because they could not reasonably head into this season with Fleury and Robin Lehner under contract. Otherwise, the Golden Knights would have had to make serious cuts elsewhere.