shocks on 2002 GMC Yukon XL Denali

If you buy 2 front, and 2 rear shocks for this car, is it normal for a price to be excessively charged the same net and list prices of $485.00 a piece? With the understanding that repair pal lists the prices to charge, I know, But on a professional "opinion", what can be reasoned for the same charges to list for net and list and then render me the consumer, that's easy 2 grand total for four shocks; and if they never get installed correctly, that's more money to pay for repairs to the shocks. Is this a normal business practice, or was I deceived?

Your denali must have the auto level system and the list price for AC Delco shocks for your vehicle is $598 each so it looks like they gave you a discount on the parts provided they are AC Delco ( standard equip for your Denali )