jmho but MCO has many tourists vs business travelers. If these boards are representative as a whole, many of those renting appear to have multiple reservations at any time. If the companies see bookings at a certain %, the deals just won't be there.
I try to book reservations in MCO early, then watch like a hawk. I'm sitting on a one-way rental for a midsize for a week the latter part of may thru Alamo for $125. It's the lowest rate i've paid in years. Booked it 2-1/2 months prior to trip date. Can't remember if I used WDW AP or Orlando Magic Card, but both produce decent rates for me. The Costco rate always little less & includes an extra driver but none near me.
I have booked with priceline or hotwire if I can't find anything within my comfort level a month or so out from my trip. Only issue is varying longish waits in the terminal to retrieve keys.