Q: They cost a lot but Im not sure if they're even high speed. What are some average speeds?
A: Wireless Air card average speed range from 11mbit/s -54mbit/s. Which is 802.11b -802.11g. The fastest 820.11g extended go up to 108mbit/s. If you are talking about the fastest WiFi card on the market, that will be 802.11n which go up to 600mbit/s while most devices today support a PHY rate of 300 Mbit/s, with the use of 2 Spatial Streams at 40 MHz. 802.11n also have higher coverage range. But most people don't need it, they stick with 802.11g which is enough form playing online movie to internet gaming.