Touring bikes are a small part of the market and good parts cost money. If you want wheels that won't pop spokes right and left, good hubs ,derailluers that hold up, a strong frame with lots of braise-ons and long wheel base, it's worth the extra cost.
Trek offers a card with 90 days same as cash.
My lbs lowered the cost of the 520 by switching to a mountainbike crankset. Best $1000 I have spent.