Consumer Affairs Minister Paul Goldsmith has welcomed fines handed down to dodgy mobile truck shop operators.
Goodring was fined $98,000 and Betterlife $73,500 for failing to provide borrowers with information about how much their purchases would cost.
Goodring was fined more because it also failed to register itself as a financial services provider.
"Many families can get themselves into a terrible tangle through debt and poor quality arrangements and purchasing," Mr Goldsmith told Paul Henry on Wednesday.
"What we're trying to do with the law is trying to ensure those lenders tell them exactly what they're going to be up for, and the cost over time."
The commission said Betterlife sold one customer an iPhone 5C for $2401, paid in instalments, while they cost only $600 in stores at the time.
Mr Goldsmith said he found one truck shop selling iPhones for $59 a week, for 100 weeks.
"That's not a good deal," he pointed out. "If you're going to have instalments like that, you need to outline the total cost - $5900. Hopefully fewer people would be inclined to think it's a good deal."
The commission says it has "a good number" of other truck shops lined up for prosecution.
"You can pass all the laws that you like, but they're only any good if they're properly enforced," says Mr Goldsmith.
If anyone thinks they've been ripped off by a mobile truck operator, he says they should go to the Commerce Commission website or talk to their local Citizens Advice Bureau.