need wireless for my powerbook g4

i have a powerbook g4 and it does not have an airport card. i bought the airport extreme and to my disappointment it does not work. and the airport origional card is the one it needs and that is no longer produced, and pretty pricy online, like 100. what can i buy so that my powerbook will connect to the wireless network in my home. all of the flash drives i see are for pc and not mac. on ebay when i search for airport cards for mac i do get this flash drive for 50 plus ship that is specifically made for macs. should i get that or are there wireless flash drive connections for my powerbook g4 that are cheaper, i know they have cheap ones for pc's. thank you. if there are not many options i will just get the one for 60 but im looking to save some money.