Quality Budget RCA Interconnects

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.

Best cheap interconnects I've tried are the Blue Jeans Cables and Signal cables - very good value IMHO.

Pony up just a few more dollars and get the Audioquest Blue Racer II exclusively from Audio Advisor. These are terminated with $40 silver RCAs and the conductors are AQ's PSC (perfect surface copper), which is AQ marketspeak for single crystal copper. I have listened to A LOT of cables through the years, and I've come to the conclusion that single crystal copper (such as Ohno Continuous Cast -- OCC) has the most consistently noticeable improvement on the sound. You won't find single crystal copper with this quality of terminations anywhere else this affordable, nor will you get as much improvement via your interconnects as these, except possibly Kimber Tonik.

Don't confuse single crystal copper with long grain copper (LGC). LGC crystals are about 1/8" long, so there are hundreds of crystal boundaries in an LGC interconnect. PSC/OCC interconnects have no boundaries because a single copper crystal spans the entire length of the interconnect.