No disrespect meant, but no one with any real software development experience would suggest that a quick formula can be used to estimate the cost/time to develop a given project. Very experienced people spend lots of time up front trying to estimate cost/time and are usually not very close.
"Is this straightforward" can't be figured in 10 minutes for the vast majority of projects. And if you are outsourcing to devs, "has the team done stuff like this" is going to take some time too. 10 minutes simply isn't enough time. Would you have the same thought about 1 minute? 5 minutes? At what point do you say "no, that isn't enough time?". I'll take a few hours as enough time for some reasonably small but not trivial number of projects as a %.
I've built or managed the teams that built over 50 software projects, ranging from small up to about half a million dollars.
With all that experience, my estimate process is now extremely honed. It takes me, quite consistently, 4 to 8 hours for a typical web startup MVP. And that's assuming I can build the product completely with technologies my team has used before.
