And the 3 apps are iPhoto, iMovie, and Garageband; which all came on the MacBook Pro when I bought it.
What happened likely is someone restored their iLife on the machine or you purchased the machine used with someone else's iLife still on it.
Since you don't have their AppleID, you can't update it. All AppStore software is copy protected.
This can occur if you bought a machine aware or unaware it was a "open box" or "used" and someone wiped the drive and reinstalled iLife with their AppleID not knowing it can't later be updated or trying not to let anyone know it's a used machine, thus having to drop it's price.
The purchaser then figures it out later that it's a used machine, have to pay for the iLife now.
You should complain to who you bought the machine at, they owe you iLife cost at least.