How much weighs your checkin?
Beeing budget-driven you have to have the right tools. The simplest thing I could come up with are the code scales, that tell you what you have got in your workspace:
(svn diff |grep -e "^\+[^\+]"|wc -l;svn diff|grep -e "^-[^-]"|wc -l;echo "-";echo "p")|dc
It once again proves the point that real programmers use unix and love RPN.