long run of RCA audio cables needed cheap

hi everyone,
I connected a TV and Directv on my boathouse Sunday. Now i can use the tv speakers, but want to hear XM radio through my speakers, so if i want to run the audio through the speakers i need RCA cables to run from the Directv receiver to my HK AVR which is about 50' away.
I checked PE and they have 12' RCAs for $13 each and female adaptors, but that is more than i want to spend.

Is there a cheaper way?
Thanks for any suggestions.

ps. the speakers are not expense so i don't need quality cables, just decent stuff to get the job done.

I believe PE sells 50' Dayton cables.

i found a good price on cablestogo.com , but they want $9.82 to ship a 1/2lb cable. Too expensive so i bought a 50' rca cable from ebay and with shipping it was $12.75.

thanks for the reply!