Unless they actually know what they are doing.
Costs are skyrocketing because of complete waste in the development process and countless stop starts. The game industry is as bad with their own and crowd funded cash as the US Government is with our tax dollars.
Mostly, if I had to make a list of the best few ways to keep costs down this would be there.
1. Have a solid idea what you are going to make, and then stick to it.
Changing things on paper is cheap, so 3 people spending a couple weeks (Designer/Coder/Artist) figuring out what you are going to make can save you tens of millions. You don't have to be married to the details, but you should write them down and plan for them. Pad all time estimates by 100%.
2. Substitute time for money.
A small, good team working longer will get the same amount of work done for
muchless money than a big team trying to finish sooner. Team sizes don't scale well on games, especially early on. The classic mistake made on bigger projects is the opposite, publishers are impatient they want that ROI as soon as possible because their bonuses depend on it. If you tell them a project will take 25 people and 2 years then they think 50 people will take 1 year. At that point they tell you to hire 100 people and give you a 6 month deadline, and make it an offer you can't refuse.
3. Pre-production for as long as necessary.
This goes along with number 2, but use your pre-production. Things are cheap here, experiment
nowbecause experimenting later will cost you millions.
4. Use Contractors.
Seriously, this can save you a lot of money, time, and effort. Work can come in bursts, sometimes you do need things quickly, usually assets like art or sound. Rather than hire like crazy and then have all these expensive people idling, it is ok to farm it out. If things don't come out well you can fix them.
5. Well Organized Data
Setting up your data correctly can drastically reduce the time it takes to make and bug fix content. Not just what we traditionally call content either, classes and abilities are content too
I could probably think of more, but those are the big ones.