Well let's just think for a second. Let's assume the person doesn't know any one in driving distance that can install the jacks for them, and they have to ship it out to some one. Let's say shipping is a modest $10 each way, and let's round up and say $25 total shipping cost. Figure the parts are like $5, that's $30. And obviously you would have to pay some one a little something for their time, so let's double it and say $60.
Weren't the cables going for about that price or more? I don't really know how high the price got, since I was never interested in paying more than $10 or 15 for them.
But let's say that the cables are $60 and for the same price you can pay some one to install the jacks for you... install the jacks without a doubt. Aside from what skate said, with standard jacks on the back of the console you'll be able to use your choice of cables. 99% of AV cables sold these days for retro consoles are 100% pure cheap garbage cables. So you'd be much better off.
Or perhaps you could trade for the service, and then it would only cost you $30 to get it done.