In recent years there have been few better indicators that Americans are feeling pain at the pump than the resale values of used hybrids. Last spring, used Prius sales rose 51.5 percent in less than three months, in response to a 25-cent increase in gas prices. Now, with the average price of a gallon gas up more than 50 cents since New Years, used car buyers are again flocking to pre-owned gas-electrics for relief.

According to Kelley Blue Book, the average value of a used hybrid at auction jumped 6 percent during the month of February alone. As reported by Autoblog Green, a KBB press release today warned used car sellers of a coming run on used hybrid inventories, predicting a possible 20-percent price increase by year’s end. “Dealers have been aggressively bidding on fuel-efficient vehicles at auction as consumer demand increases,” read the release. “Kelley Blue Book advises dealers to stock up on inventory sooner rather than later, since values likely will increase sharply during the next 30 to 60 days.”

The nationwide average price of a gallon of regular unleaded now stands at $3.87 according to the EIA’s fuel price index website―up 3 percent over last year’s levels. On the west coast, drivers are paying average of almost $4.20 per gallon.

Increased popularity of affordable hybrids has also been reflected in sky-high demand for Toyota’s latest hybrid release, the Prius c. The baby of the Prius family elicited orders exceeding 10 times its planned monthly production target since hitting the market in Japan, and one Toyota dealership in Miami has reportedly been charging a $7,000 markup on the car in response to high demand.

New hybrids on the whole did very well in February, up more than 35 percent over 2011 levels, and by all indications, March’s numbers are likely to again be impressive.