As someone looking to do this myself I can tell you. Any good studio these days charges at least $100/hour for time recording. Even if you walk in ready to go, it can take 4 or more hours to record one song. More if there are complicated production tasks like auditioning different guitar amps or vocal mics.
At some studios, their price includes an engineer, but often a good engineer charges extra. Once the song is recorded, a separate mixing engineer will take the raw tracks and make a finished mix. Then a mastering engineer will polish them further for different markets including radio or AAC. And if you need or want a producer, arranger, cowriter, or session player, you have to pay them for their time. All the while you need to eat and pay rent as an artist or band.
$10k is an average budget for a short album, and consider to break even an artist must sell 13,000 songs if independent through iTunes, more if they split revenue with a label. How many artists have less than 13,000 fans? This is why many record deals today include touring revenue as part of the contract, because they know they can't sell enough downloads to recoup the cost.
Those costs will highly depend on the kind of music and your ambition. In my opinion many artists do not actually need professional mastering. If recording an album is a loss anyways, why not make your music free and see if you can find enthusiast hobbyists to do the fine tuning for free as well.
It's certainly easier to DIY these days for some things -- electronic music comes to mind, but there's no replacement for a properly treated studio with all the appropriate equipment on hand. You get what you pay for.
> many artists do not actually need professional mastering
Almost everything sold commercially has been mastered, the only stuff I have heard unmastered is on Soundcloud/Youtube for a reason. Having a skilled third party polish a track is essential.
> why not make your music free
Why is this acceptable for a musician but not for a film director, actor, programmer, or any other career professional? Should all films now be made DIY with volunteer actors and we'll just have hobbyist special effects and post added? What are these hobbyists supposed to do to pay rent and eat?
Music is an expensive business, and digital downloading hasn't changed that. That's why it's frustrating to hear people feel entitled to free music, even if there's not much we can do to change it.
At some studios, their price includes an engineer, but often a good engineer charges extra. Once the song is recorded, a separate mixing engineer will take the raw tracks and make a finished mix. Then a mastering engineer will polish them further for different markets including radio or AAC. And if you need or want a producer, arranger, cowriter, or session player, you have to pay them for their time. All the while you need to eat and pay rent as an artist or band.
$10k is an average budget for a short album, and consider to break even an artist must sell 13,000 songs if independent through iTunes, more if they split revenue with a label. How many artists have less than 13,000 fans? This is why many record deals today include touring revenue as part of the contract, because they know they can't sell enough downloads to recoup the cost.