A quick bit of bash that you can do from the command line on linux (or MacOS, if you have lame installed)…
SAVEIFS=$IFS
IFS=$(echo -en "\n\b")
let i=0
for f in `ls *wav`; do
let i++;
lame -h -b 192 $f `printf '%03d' $i`.mp3;
done
IFS=$SAVEIFS
(The IFS stuff is so that it will work with filenames that have spaces in them)