By all means blow the cash on a stack of discs, but is this all at once? Money wasted to me - you'll buy a load of them, and for £350 that will be a load especially with the price of CDs right now and you'll not get round to listening to them all. Spread the purchases throughout the year and spend time listening to each of the albums.
I buy a lot of discs, but not so many that I don't get time to listen to them all a few times round. Up to you of course, but this would be my preferred way to go.
As for which one? The debut Jepp album (you'll need to shop around for it) and Joni Mitchell's "Night Ride Home" album which will double up as a test CD for the title track.