Best way for two users to work on the same FCP X Projects?

Imho....

best way is a part of my nick: Xsan

No cheap in the original form, but right now it is integrated in the OS X Server versions. Will be worth a look, anyways....

 

I was looking for an answer to this too. I went into the Apple Store to see if their most brilliant "Genius" had a good solution for me.
He didn't. I don't think there is any real cheap option other than getting an external hard drive (which can be slow to edit off of in certain situations unless you have thunderbolt and the external is an SSD or RAID 0).

 

Buy a second hardrive drive and keep the contents on the two drives mirrored? Beyond that and you are looking at shared storage solution. With GigE you can get fast speeds for a lot less than fibre but you are still looking at something more complicated than plug-in-play. If you are, or have access to, someone that's technically minded and good with networking you this can be a DIY project.

This is a relatively old article from '08 on building your own SAN but the basics haven't changed.

Build your own affordable SAN -- that works!