Clean wiped Mac, can't re-install Mavericks anymore.

Question

So, I have a MacBook Pro that was running Mavericks that I recently tried to factory reset with a clean wipe. However, I didn't realize until after wiping my machine that Mavericks is no longer available on the app-store and I haven't previously purchased it either. I don't have any backups either, so there's nothing I can restore. So now I'm stuck with an empty machine that only gives me the option to install Mavericks, which is obviously unavailable.
I'm willing to upgrade to Yosemite (though I'd prefer to stay with Mavericks) if there's a way to install it onto the machine. Anything to get this thing running on an OS again.
Thanks in advance for the help.

Answer 1

Is this what you're seeing (or something very similar)?
If so, that's the recovery mode work screen. It looks the same in either recovery mode. The main difference is Command+R boots to the hidden recovery partition on the hard drive, and Command+Option+R boots to the firmware and isn't working off of the hard drive at all.
Disk Utility can't be the function asking to reinstall Mavericks since it has no part in installing the OS. That would be the Reinstall Mac OS X button.
It keeps trying to download Mavericks because that's what's on the hidden recovery partition. You need to remove that so the Mac is forced to install its original OS.
Startup, or restart the Mac and immediately hold down the Command+Option+R keys to boot into Internet Recovery Mode. Note: it's better to use a wired Ethernet connection to your cable or DSL modem rather than wireless for this.
You will get what looks the same as a normal recovery mode restart, except you're working off the firmware rather than the hidden recovery partition. You need to do this so Disk Utility can wipe the drive since you can't remove the startup partition out from under yourself if you used Command+R.
Launch Disk Utility and select the physical drive name in the left pane.
With the physical drive selected, click on the Partition tab to the right. Where the graphical display of the current drive layout says Current…
…change it to anything other than Current. If the drive is one partition for the whole thing, and that's what you want, then choose 1 Partition from the drop down menu. Note that the hidden partition is not shown in this display unless you turn Disk Utility's debug menus on (you can't do this in Recovery Mode). It is there, and that's what you need to get rid of by repartitioning it.
I'm going to assume one partition as your choice. After changing the menu to 1 Partition, give the drive any name you want in that field. Click the Options button to make sure the radio button choice is GUID (it already should be). The format should also default to Mac OS Extended (Journaled). Click Apply. It will take just 10 seconds or so to repartition the drive.
Quit Disk Utility to get back to the main menu and choose to reinstall OS X. With no reference for any other OS on the drive, the Mac will reinstall the original OS it came with from Apple's servers. It will also recreate a new hidden recovery partition to match the OS level it installs.
Once it's done and the Mac restarts to the newly reinstalled OS, you can either apply any updates available and leave it at that OS, or you can create your own App Store account and then "purchase" and install Yosemite, 10.10.x.