Mine was between $50 and $75 bucks.
You want something like this:
I had to buy the RCA to 3.5mm cable myself, so that will add about 10 bucks to the cost. Also since my Chevy doesn’t use the standard antenna leads, I had to convert that too. (I hate chevy)
If you have any knowledge of car stereo installation it’s a breeze. Simply shunt this unit inbetween the antenna lead wire and the antenna jack on the back of your car stereo. Hook it up to a 12V source in the car, and You’re good to go. I suggest you tie the hot lead to a lead that is only powered when the car is either in acc or on, or otherwise you might inadvertantly discharge your battery if it’s hooked to an always on source.
Once it’s installed, you set the stereo to whatever channel you preset on the modulator, and you will feed the Sansa beautifully. Just like the wireless ones, though, you need to turn the Sansa’s volume at max to get a good clean signal. The “on/off” switch is used to turn off the modulator when you are actually using the car radio as this unit will usually black out a good portion of signal surrounding the “preset” and when it’s on, AM reception is completely gone.
This is still not the best solution. If my Chevy had a cheap way to add a third party stereo I would have done it, but the harness for my car stereo is outrageously expensive. So, this is a good alternative. Plus, with a factory installed stereo in my van, I escape the notice of many would be stereo theives.