This item is temporarily unavailable

It would be helpful if you indicated the EXACT model/year MBP that you have.

Ciao.

The error message is misleading. In fact, the item—an obsolete version of OS X—is permanently unavailable in Recovery. You will have to reinstall the original OS, or OS X 10.6 (if you have an older model), and then upgrade to the current version in the App Store.

If the machine shipped with OS X 10.4 or 10.5, you need a boxed and shrink-wrapped retail Snow Leopard (OS X 10.6) installation disc from the Apple Store or a reputable reseller—not from eBay or anything of the kind.

If the machine shipped with OS X 10.6, you need the installation media that came with it: gray installation discs, or a USB flash drive for a MacBook Air. If you don't have the media, order replacements from Apple. A retail disc, or the gray discs from another model, will not work.

To start up from an optical disc or a flash drive, insert it, then restart the computer and hold down the C key at the startup chime. Release the key when you see the gray Apple logo on the screen.

If the machine shipped with OS X 10.7 or later, you don't need media. It should start up in Internet Recovery mode when you hold down the key combination option-command-R at the startup chime. Release the keys when you see a spinning globe. Note that Mac Pro tower models older than late 2014 (with the "cheese-grater" enclosure) cannot use Internet Recovery, regardless of which OS version they shipped with. The round Mac Pro (2014 or later) can use it.

Some 2010-2011 models shipped with OS X 10.6 and received a firmware update after 10.7 was released, enabling them to use Internet Recovery. If you have one of those models, you can't reinstall 10.6 even from the original media, and Internet Recovery will work only if you know the Apple ID and password that were used to upgrade. If you don't have that information, contact Apple Support, or take the machine to an Apple Store or another authorized service provider to have the OS installed.

Once you have OS X 10.6.8 or later installed, you can upgrade to the current version of OS X (if the hardware supports it) in the App Store.

If you can't run the current version, or don't want to for some reason, you'll have to contact Mac App Store Customer Service for a redemption code to download an older version.

I suggest that you use the original installation disk and reinstall Snow Leopard. When done, run the Snow Leopard combo update:

https://support.apple.com/kb/DL1399?locale=en_US

That will then allow you to install any newer OSX.

Mavericks is no longer available, but if you had it installed earlier, then it should be in your App Store account. If not, then consider installing Yosemite, which is free.

Ciao.