I'm trying to budget for my dev shop and compare our budget items to industry expectations. I'm hoping to find some information on what percentage of a dev's salary is generally spent on tooling, both hardware and software. Where can I find such information?

If instead there is a source that looks at raw dollars that is useful, too. I can extrapolate what I need from that.

NOTE: Your anecdotal evidence from your own job will not be very helpful. I'm looking for industry average statistics from a credible source.

EDIT: I'm reluctant to even keep this question going based on the passionate negative responses of commenters, but I do think this is valuable information (assuming anyone will care to answer) so let me make one attempt to clarify why I'm looking for this information, and then leave it at that. I'm not sure why understanding and validating my motives is a necessary step to providing the information, but apparently that is the case, so I will do my best.

Firstly, let me respond to the idea that us "management types" shouldn't use these types of metrics to evaluate budgets. I agree in part. Ideally, you should spend whatever is necessary on developers in order to keep them fully happy and productive. And this is true of all employees. However, companies operate in a world of limited resources, and every dollar spent in one area means a dollar not spent in another. So it is not enough to simply say "I need to spend $10,000 per developer next year" without having some way to justify that position. One way to help justify it is to compare yourself against the industry. If it is the case that on average a software shops spends 5% (making up that number) of their total development budget (salaries being the large portion of the other 95%, for arguments sake), and I'm only spending 3%, it helps in the justification process.

So, it is not my intent to use this information to limit what I spend on developers, but rather to arm myself with the necessary justification to spend what I need to spend on developers to give them the best tools I can. I have been a developer for many years and I understand the need for proper tooling.

Next, let's examine the idea that even considering the relationship between a spend on developer salaries and developer tooling is ludicrous and should be banned from budgetary thinking. As Jimmy Hoffa put it in their comment, it's like saying "I'm going to spend no more than 10% of median employee salary on light bulbs and coffee from now on.". Well, yes, it is like saying that, and from a budgeting perspective, this is a useful way to look at things. If you know that, on average, an employee consumes X dollars of coffee a year, then you can project a coffee budget based on that. And you can compare it to an industry metric to understand where you fall: do you spend more on coffee than other companies or less? Why might this be? If you are a coffee supply manager, that seems like a useful thought process. The same seems to hold true for developers.

Now, on to the idea that I need to compare "apples to apples" and only look at other shops that are in the same place geographically, the same business, the same application architecture, and the same development frameworks. I guess if I could find such a statistic that said "a shop that is exactly identical to yours spends X on developer tooling" it would be wonderful. But there is plenty of value in an average statistic. Here's an analogy: let's say you are working on a household budget and need to decide how much to spend on groceries. Is it enough to know that the average consumer spends 15% on groceries and therefore decide that you will budget exactly 15%? No. You have to tweak your budget based on your individual needs and situation. But the generalized statistic does help in this evaluation. You can know if your budget is grossly off from what others are doing, and this can help you figure out why this is.

So, I will concede the point that it would be better to find statistics that align to my shop, though I think any statistics I could find would be useful for what I'm doing. In that light, let's say that my shop is mostly focused on ASP.NET web applications. That doesn't map perfectly to reality because large enterprises have very heterogenous IT environments. But if I was going to pick one technology that is our focus that would be it. But, if you were to point me at some statistics that are related to a Linux shop doing embedded Java applications, I would still find it useful as a point of comparison.

SUMMARY: Let me try to rephrase my question. I'm trying to find industry metrics on how much dev shops spend on developer tooling, both hardware and software. I don't so much care whether it is expressed as a percentage of total budget or as X dollars per dev or as Y percentage of salary. Any metric would be useful. If there are metrics that are specific to ASP.NET dev shops in the Northeast US, all the better, but I would be happy to find anything.