I get from amazon (french, but you can check for your country)
Mini PCI-E to PCI-E Wireless Card w/ 3 Antennas
3 antenna + 3 cables
if you buy 2, you can populate 3 galileo
the price is 9$ for 3 antenna + 3 cables
so 3 $ for one antenna + 1 cable : not so bad
The Intel® Centrino® N-135, Intel® Centrino® Advance-N 6235, Intel® Centrino® Advance-N 6205 use a Hirose U.FL connectors. I am using the Antennas WLAN DUAL BAND ANTENNA. I would suggest taking a look at Sergey’s Blog - Intel Galileo Meets Wireless he covers the wireless card in great detail. Note that the Linux Image for Galileo has the driver for N-135 preloaded. To install the driver for other wireless cards see Sergey’s Blog as well.