Another way to reduce the storage required for SAS tables is the compress=char option.
It won't always reduce the storage required, but for tables with a lot of white space (wide character columns that are not always filled) the saving can be substantial.
data demo_wide (compress= yes) ;
length wide1-wide20 $32760 ;
do i= 1 to 100 ;
generates these messages[pre]NOTE: The data set WORK.DEMO_WIDE has 100 observations and 21 variables.
NOTE: Compressing data set WORK.DEMO_WIDE decreased size by 98.00 percent.
Compressed is 2 pages; un-compressed would require 100 pages.
NOTE: DATA statement used [/pre]Of course you won't get 98% decrease when you store data, but I suspect if SPSS can store the information in a much smaller space, then the compress option on your SAS table would reduce its demand for disk space too.