I ran into the same frustration with the brokers. They "advised" that we were offering too low and acted as though we were wasting their time. (They weren't that blatent...that's just how I felt.) BUT, we kept looking at listings on several sites and offering what we wanted. We weren't in a hurry...just waiting for the right contract with motivated sellers. We ended up with an accepted offer and are now waiting to pass ROFR.
Seller asked around $69 for AKV, no previous year points advertised, all of this year points. We offered $55. They countered with $63. We countered with $56 which they accepted. Later we found out that they also had 94 points banked that weren't advertised--bonus! Also that they pay MF monthly and we would only have to pay the remaining of this year's fees-great! It just kept getting better! Honestly, I think those of us poking around on this board are more educated about resales than the brokers.

Just decide what deal is desirable to you and seek it out. Be patient or more willing to negotiate higher if you're not patient.
FYI...my target for BWV was $45, SSR was $50, and AKV was $55. A big reason we are adding on more points at this time is because such great deals can be had. Don't let the brokers bully you.