#example File1
bob smith 100
tim zim 123
ted fred 450
bob hill 543

#get the sum of column 3
awk '{total += $1} END {print total}' File1

#example File2
bob smith $100
tim zim $123
ted fred $450
bob hill $543

#remove the '$' and then get sum of column 3
awk '{gsub(/\$/,"");total += $3} END {print total}' File2