It's the penny-wise pound-foolish issue when engineers and developers are forced to be mindful of schedules and business objectives. We in essence become as brain damanged as our managers, and start behaving irrationally.
It's well known we have absolutely no capacity to estimate schedule accurately, but we do have the "gut feel". If your gut says that it will take a day to implement functionality, assume it's a week and just do it, it's trivial. If it says 2 weeks, it's actually 2 months plus three squirrel years and a llama month divided by e^-jwt, maybe spend a day or two evaluating options. If it feels like 6 months, try very hard to find something OTS, because this may become the project you're working on when you retire (which in todays parlance means: you die in your swivel chair of old age).
You could of course be entirely wrong. Last week in fact I decided modifying a script to do what I need would take at least a month, had an epiphany in the shower and had it done in 6 hours. Guts have failed even Homer Simpson. But unless someone comes along who has been-there-done-that with a better option, and who demonstrates he' serious by NOT trying to railroad you in a meeting, but in fact just walks by the cube and says "hey, use this", you're usually better off trying it out yourself. At worst you waste some time but learn the problem, and how to best evaluate other solutions that come up.