I've found timing is everything. Usually do a search on kayak, skyscanner and car rentals.com as soon as I know my travel dates - make a reservation that can be cancelled up until 2 days prior to pick up. Check again periodically and I often find something at as much as 50% cheaper so cancel the initial booking.
Separate annual excess insurance policy too - perhaps £50/annum and has paid out no quibbles when a rental firm has fleeced me for a tiny scratch (against expectation, I've only had supposed 'big reliable' firm Hertz do so).
But yes, on your original point, prices do appear to have leapt upward