Some cleaners are budget/low-cost providers, but at what cost to possibly your health and carpet cleanliness. By doing a job cheap there is a sacrifice being made somewhere, possibly in the quality of work and the desired outcome, which may not even be visible to the eye.
We have all used a home shampooer or rented a low power portable unit, but you’re hiring a professional cleaner- your goal is ultimately the cleanest carpet possible.
Often cheap products are used to save money. Good chemistry isn’t cheap, and while budget chemicals may do the job, they aren’t the answer. They aren’t good for your health, the environment, and may even cause your carpets to re-soil faster.