The SGI one with up to 2048 cores are larger in their single system images than most people have in their clusters.
The benefit of these systems is not really the ease of programming but the speed of interconnect.
List price of the Oracle one was 3 million a few years ago. But most of that is actually in the high density dimms. These days I think the price must be lower, but I won't waste my Oracle sales contact time in figuring out what it is today. Of course it will still be expensive, it is an Oracle product after all.
However, an equivalent dell list price cluster of simple 1U boxes (512 6C/64GB ones!) will go for 1.5 million. The fact that to house 512 boxes i.e. 25 racks or so plus networking.
Of course you do get 1/3rd more cores than the SGI one.
For many of us that are between the just use a single normal server and yet too small for the google solutions. These big memory solutions from Oracle and SGI can make sense even if they are not the first thing that comes to mind!