hard to specify accurate amounts in software development...
hire & onboarding of new ppl or train existing ones, check the old code, after that develop... I don't think you can (and should make such promises).
This needs to be agile. E.g. here is a ordered list of priorities we start with the top 10, then the developer goes on and on implementing by priority, ensure that there will be always a working test build to compile available.
when there is only a specified amount of time or money left, the remaining time will be used to bugfix + create a stable version.
BAM
