Here's the arithmetic that makes this article necessary. The park fees are identical for every operator. The minimum crew wages are set. Add the food and the transport and you get a number below which a climb cannot honestly be sold. If a quote comes in well under that, the difference has been taken out of something, and it's worth knowing what.
Usually, the crew
Fewer porters, so each one carries more than the limit. Wages below the agreed rate, or wages paid late, or a share of your tip quietly kept back. No proper boots or jacket for men sleeping at 4,600 metres. It's the easiest cost to cut because the person being cut isn't in the room when you book, and won't complain to you on the mountain.
Sometimes, the food and the kit
Thin sleeping mats, leaking tents, not enough hot water, meals that don't give you the calories you're burning. None of it is dangerous on its own. All of it makes you more tired, and tired is what turns people around.
Sometimes, the safety margin
This is the one that matters. No pulse oximeter, so nobody is measuring how you're doing. No bottled oxygen, so there's nothing to give you if things turn. One guide for a large group, so if somebody has to go down at two in the morning, either everyone goes or nobody does.
And often, the days
The cheapest climbs are the shortest, which is why they're cheap. That's not dishonest in itself, as long as the operator has told you plainly what a five-day profile does to your chances. Most don't.
Questions that get you a straight answer
How many porters for our group, and what's the weight limit you weigh them at? What do the porters get paid, and when? Do you carry oxygen and a pulse oximeter, and who checks us? Is the crew insured? An operator running a clean mountain answers all of that without hesitating, because they're proud of it.
How to check independently
The Kilimanjaro Porters Assistance Project publishes a list of operators that have agreed to be monitored on wages, loads, meals and gear. Being on it isn't the only sign of a decent company, but it's a check you can do yourself in two minutes, and it's better than a badge on a website.
The honest bottom line
There's nothing wrong with wanting to spend less. Do it by choosing a bigger group or a less elaborate camp, not by choosing the operator who undercut everyone. The saving in that version comes from a man carrying your tent in trainers.
Where you can honestly save
Hire the big kit in Moshi or Arusha instead of buying it: a down jacket, a four-season sleeping bag and poles cost a fraction to rent and you'll probably never use them again. Join an open-group departure rather than booking a private climb. Travel in the shoulder months. Skip the private toilet tent if you can live without it. All of those take money off your bill without taking it out of somebody's wages.