Ask HN: What are OK tasks for a freelancer to bill?

I'm currently working with a (good) freelance designer via oDesk, however she has spent quite some time installing/configuring her system in order to work on my project (git, python, mysql, installtion problems etc). She already billed more than $300 for that and given I'm spending my hard-earned money, it's a bit hard to swallow. She also billed time for looking at inspiration websites in order to get a feel of what needs to be done.

Do you consider it normal for a freelancer to bill for inspiration research/system installation?