The answer would be that some people will pay for it. They obviously don't care about selling a ton of memory chips, so their price is optimized for something else.
A similar situation may happen as a contractor: there may be gigs that you'd rather not take, so you will ask for an ridiculous hourly rate (say $700/hour). If they pay for it, oh well.
Installing memory is probably a lot of fuss, especially for such a streamlined manufacturing process, and they can't post a fluctuating market price, so they just post one they can live with no matter the circumstances.
A similar situation may happen as a contractor: there may be gigs that you'd rather not take, so you will ask for an ridiculous hourly rate (say $700/hour). If they pay for it, oh well.