Naughty School Girls / Zero in and Scream (1975)

In Naughty School Girls (1975), a group of private-school seniors want to raise money to buy a new bell for their school, so they hit on the idea of putting themselves on the market. In Zero in and Scream (1971), a lonely man, tired of being rejected by women, gets ahold of a rifle and prowls the Hollywood hills, picking off rich couples.