Why doesn't your friend ask these questions of her LBS??

My shop will swap out components for you, mainly free of charge on new bikes. You may pay for the difference on a part, if your new part is more expensive, however. It's part of the whole fitting and getting the bike right for your process.

An economical price for pedals depends on what kind of pedals she wants and what she's willing to pay. For some, $20 for standard cage pedals is good. For others, $200 for ti pedals is a good thing.