It would depend on what store you want to use, but NCIX for example has an i3 540 for $106.98. It's a first gen i3 though and uses LGA1156 instead of LGA1155 like the newer ones.
Are you just looking to build a cheap PC with Intel?
"Are you just looking to build a cheap PC with Intel?"
I was thinking the same thing
LGA 1156 mobos are harder to find and are more expensive now so it is probably better to get a 2nd gen i3