Three rifles that are consistently undervalued:

The Feinwerkbau 300-series recoilless springer. Possibly the finest fixed-barrel non-hunting air-rifle ever made. Consistently changes hands slowly and at a far lower price than heaps of utter, utter rubbish.

The Walther LV55. Possibly the finest non-hunting recoilling springer. As above.

The Baikal IJ38. A sturdy, well engineered springer for juniors or beginners that is extraordinary good value, yet sells far more slowly than C02-powered crepe suzette at twice the price and half the quality.

Buy quality kit, don't be a bonehead!