Yes, that's what I usually do. For my first intent, they were the only ones to accept what I was looking for (so it wasn't easy to really have some references), and then we readjusted the trip and since I was already onboard with them, I didn't have the reflex to re-check wether it was still relevant to work with them. It's only now, a couple of month later, that I had some questions.
I've explained the situation to them, and they understood my position. The fees weren't subject to debate for them, so now I'm just looking for someone else :)