GoneDragRacing.com

I am ready ton purchase a race weather station. Been doing a lot of research as they range in price from $200-$3000. Does anyone out there have expiereance with weather stations. It appears to me an oxygen sensor would only be needed if racing different states, oxygen levels don't change at one location, or does it? The oxygen sensor option is roughly $200. The otherone that doesn't make a lot of sence to me is wind speed, in the case of a hand held it won't tell you direction so what good it that options?

HELP