Here's my puchasing power: "Boss, if we buy this developer tool it will save X hours of developer time." ... where X is large compared to the price of the tool. It works well enough that we use it often enough for Boss to be skeptical.
And skeptical they should be. Overestimating benefits, whether it's for a tool or something like a re- architecture, is right up there with underestimating effort, probably highly related...
Doesn't mean there aren't worthwhile tools, because there are, but they're few and fast between.
How much time before you boss says: "OK, during the last 3 months you told me that all these tool would save you in total 1 dev/year... so I will reduce your team by 1 dev but keep the work and deadlines" ? ;-)
I had this happen. I was on a team that was overloaded by work generated by another team, that had the tools and capabilities to automate the work, but chose not to, because they didn’t have to deal with it. Spending time on their work meant other important tasks went undone, or were half assed.
I pulled some data and did some math, and found that we could dedicate 3 people full-time just to working on their junk. My goal with this was to light a fire under them, get that stuff automated, and free up those hours so those people could do more interesting and worthwhile work.
It did light a fire, the stuff did get automated, and the week after victory was declared, 3 people were laid off. I was very upset and yelled at my boss a lot. It sent a very clear message to everyone on the team that automation is the enemy and when they see something they can/should be improved, they’d be smart to keep their mouth shut. That’s exactly what happened. Improvement efforts ground to a halt, as no one would talk about issues or use new tools that were developed.
