2001 e39 replacement bulb

[timabe]

Ok, I'm sure that this is not as complicated as it seems....

The right lowbeam bulb on my 2001 525i is out. I have pulled the bulb unit out and it is marked Hella H7. Questions:

1. I have seen replacement bulbs referred to as Xenon, OEM, high-intensity, blue, yellow, 55w, 100w, etc..... I have also seen replacement bulbs priced from $4.99 all the way to $125.00. What's up with that? What bulbs do I need anyway?

2. My original sticker tells me I have "halogen free-form lowbeam headlights and fog lights". What do I have for highbeams? Can the highbeams be replaced with halogen? If so, is this as easy as installing different bulbs?

Thanks for any and all help.