Quality Budget RCA Interconnects

Acoustic Research

http://www.hififorless.com/showProduct.php?productid=54547

I've used the G-snake. Its a very solid option.

Older MIT terminator 2 or 4 used are other very good options to try overall.

DNM Reson is another I like with a different, somewhat warmer and more "British" sound, much like B&Ws, that can work nicely in systems that can use that.

Check out these guys, especially their "expensive" cables (eKs):

http://www.knukonceptz.com/productMaster.cfm?Category=RCA%20Interconnects

-RW-

AR cables are quite good for the money, and AQ cables for sale at HCM audio are a bargain.

The ultimate from the budget IC universe may come from Auricle Audio Design: hand crafted with a proprietary RCA jack design from Audiogon member Joemazzaglia.
I don't know if the latest 2009 price is still close enough to your budget, but these have been inserted by me in some mighty fine systems with surprisingly impressive results.
Not long ago there was an Audiogon ad for his newer even lower cost entry level model which I have not had the pleasure of auditioning, but if it is anything like the original then your $40 price could get you a very cost effective solution.
Regardless of how a manufacturer prices his/her product, the great wires reveal more of what your system is capable of delivering, starting many an audiophile along that lifelong upgrade path.