I recall, you have mentioned in the past that the Travel Agent topic never came up when you were on board. I would encourage you to make another attempt on your next cruise.
It’s not necessary to ask someone how much they paid for their cruise, just let them know you’re looking for a good travel agent, and do they know one they can recommend to you. Also, good to ask why do they like their travel agent.
Not everyone uses a travel agent, and some people are not satisfied with their travel agent that they are using, but most people are eager to support their travel agent by passing along recommendations to new customers like you. Good luck.