I have booked a fair amount of award tickets myself (usually 10-15 a year) and have never had an experienced where they raise the amount of miles needed before ticketing. I have had them ask for more miles after ticketing and before traveling if I wanted to change a flight, even same route, same date - just slightly more direct. But that is different (and I didn't pursue it).
10-15 per year, I do not begin to have the patience to book that many flights per year with points.