Yup, if you need 10 million for a project, you quote 3 million and ask for more funding later on, otherwise you will never get any funding at all as they balk at the true costs of research and development.
We have a benefits tracking requirement, you put in a 3 gets you 9 case (borderline fundable - probably too small and not sufficient payback, but you might get it) and they go back and ask for another 7 over 2 years and you will leave on the ask. If you put 3 gets you 30 and then ask for another 7 you may well leave on the ask, you may get to stay for the realisation of the 30, but then you go. Probably you go on the ask because someone else will be parachuted into the project (if it's believed that the 30 really is on the table).
But when I was there it was already being worked around... managers would create lots of smaller projects that delivered cross-functional behaviour to multiple projects and allowed them to externalise and hide the overages in what might appear to only be dependency lines to existing internal projects. The managers of multiple projects would collude to sponsor each others externalities so that they all had a layer of protection from being fired, obscuring what the costs were actually contributing to.
The reason I was there was precisely to build a revenue recognition type system for their project management system to try and identify which projects had asked for some other project to start.
But after that I worked at a UK govt department and they'd become so good at tracking who had been first to demand the creation of another project that their problem became one of legacy... no-one could sponsor even upgrading their long obsolete software or hardware, because even though it was a thing that benefited everyone, the project that demanded it was going to be the one that paid for it (literally paying for the certification, hardware, software, training, etc) which meant if you were the team that said "We can't support this on IE6" then you had to pay to replace laptops, OS, to get onto a later version.
My conclusion... if we don't embrace a pragmatic reality of what things cost, if we try and manage the costs tightly... the side effects usually have unintended consequences that are worse than facing or embracing the original costs.
Yes, but sometimes there is competition between projects. In that case it may pay to lie about the actual cost.
If so, I would see only two rational approaches: find another job, or hugely overestimate, and, unless things go very wrong, twiddle your thumbs for most of the time (or think of/work on a side project or study)
It’s very hard to estimate even the simplest ‘projects’ within 10%. For example, try estimating how long your trip home or your next bathroom break or coffee machine visit will take, and see how often you get within 10% (if you say “5 minutes” that gets you 30 seconds either way)
Underestimating on the contrary leads you to not getting funding for the projects you are responsible for, and that is a nice way to not get a promotion.
As in Python, it is easier to ask for forgiveness than permission.