The 'Classic Series' (2088 Model) and the 'Extreme Series' (Smart Sensor 4900/5900 Models) were discontinued
The 4008 Revolution (3 gpm/55 psi) is direct replacement for 2088 Model
and the 4048 High Flow (4 gpm/55 psi) is intended as replacement for the Smart Sensor Models
ANY 2088 pumps still fr sale are NOS (New OLD Stock) that have been sitting around........more expensive than newer replacement pump and parts availability very limited. Why buy old out dated?
That Amazon link lists 2088 at $72 and the 4008 at $60
PPL has the 4008 at $53....
LINK