Code:
~# repquota -asu
*** Report for user quotas on device /dev/hda1
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
root -- 1854M 0 0 47993 0 0
.....
ispconfig -- 27992 0 0 5412 0 0
web1 -- 76 200M 201M 22 0 0
web2 -- 84 0 0 23 0 0
#105 -- 4 0 0 1 0 0
s is for human readable Oo
Looks like only big numbers get a size
Edit2:
maybe substr the last number or letter -> if its a number you can write KB