If you looked these up live then it's not a realistic comparison as there are multiple Advance fare levels for each station pair, with a limited number of tickets in each basket. It would be very surprising if Preston and Lancaster were both currently in the same basket.
If you want to make a comparison you need to use a site such as BRFares.com which allows you to compare the actual baskets rather than the tickets currently available.
As I said earlier, if you scroll down to the standard Advance tickets for
Preston and
Lancaster you'll see that the top three baskets are: £148 v £148, £145 v £146, £128 v £128.50. So Advance tickets to Lancaster are the same price or slightly more expensive than the comparable Advance ticket to Preston.
If you're going to get outraged, at least make sure you're not comparing apples to oranges.