Final answer:
Bath salts, which contain MDPV, are often used as cheaper alternatives to cocaine due to their stimulant effects that are similar to those of cocaine.
Step-by-step explanation:
The drugs that are often used as cheaper alternatives to cocaine include bath salts, which contain a psychoactive substance called Methylenedioxypyrovalerone (MDPV). MDPV acts as a norepinephrine-dopamine reuptake inhibitor (NDRI) and was previously sold as a designer drug in products labeled as bath salts. While LSD and PCP are hallucinogens and dissociative drugs, respectively, and methadone is typically used as part of opioid treatment programs, bath salts are a more direct alternative to cocaine in terms of the stimulant effects sought by users.