What happened to AM/FM tuners is that without content, they essentially became worthless. And what happened to FM radio is truly a crime against humanity. The FCC should be locked up in jail and sodomized nightly. They let the corporate foxes rule the hen house and now we have nothing worth listening to on FM except for NPR.
If you purchase an FM tuner, all you will find is coporate pre-packaged pablum off a digital music server that stores the music in an MP3 format. Oh and now we have plenty of spanish-language stations to choose from and more commercials than you (or anyone) can stand. None of which is worth spending $75.00 to listen to.
So, while you can still find new and used AM/FM tuners available to buy, why would you want one... they're just a waste of money and shelf space.
One of the biggest problems that I had with trying to listen to FM is the fact that most of the stations pump the bass about 12 to 15 db and the music sounds way too bass-heavy on a decent system.
Now the hype is all centered around HD radio. Broadcasters want you to invest in a new service to stream commercials into your home,car, or office. The HD radio system uses part of their FM bandwidth allocation to stream 100, 112, 125, or 150 kbits/second of lossy data to HD receivers. The actual rate is set by the station depending on power budget and desired range of signal. By comarisson, a CD has between 900 and 1400 kbits/second of data. In listening to HD radio, the sound has a time domain distorion to it that becomes tiresome after about 5 minutes and irksome after about 15 minutes. While this would be fine for your car (at least the meta-tags are useful), it really doesn't make sense for a high quality 2-channel audio system.
The new replacement for FM is internet radio or satellite radio. You are far more likely to be happy with either of these technologies than if you buy a new AM/FM tuner.
