Technical Salespeople – What a concept!
I guess this really isn't the fault of the tech salesforce, but it's the illusion that they are really providing something in the transaction. Oh, sure... there are some turn-key solutions where all we really need to do is to buy the hardware - speced out to the last detail, get the install disks from the vendor and that's basically it. But those solutions are really few and far between. Most big systems have to interface with systems in-place in your Shop so it's not a plug-n-play solution. Which is the supposed reason for the technical sales force (aka consultants) from the vendor.
Here's what happened... we have asked the vendor to be on the next version of their product - something that's a complete re-architecture from the currently shipping version. Totally different. But in a way, that's good. The existing system was a mess and could not possibly do what we need, and the new system may be new and green, but at least it's got a chance of being the 'right thing'. So we need some hardware to run this beast on, and I put together a list of a minimal set-up to get us going. I know it's probably not enough, but it's close and has a decent chance of being all we need for production. I send this to my manager, explaining why I've chosen this configuration, etc. and said "Approve this and we get moving". One of the guys who's not above me in the org chart, but has fewer boxes to the Big Boss said to run this by the tech sales person and see if it's OK.
Normally, I'd say "Great!", in fact, I would not have made the list myself but asked them for a list. But that's not really possible now. There's a totally new architecture that they've never delivered to any client, doing things that they never did before. How do they know what our situation is going to take? They don't. But even if they did... my guess was 'reasonable' - let's say the knew what it'd take. If it was less than this I'd be very surprised because the system we have now doing this task is using this same hardware and only doing a fraction of the job this system will be required to do. So doing more for less? Hmmm... then there's the fact that the existing system is all in C++ and this has significant parts in a scripting language. While I'm not saying it's slow, I am saying I'd be very surprised if it were faster than what we have now.
So let's say it's slower, and they know it. Are they going to say "Hey, this is only about half of what you need." Not a chance. We'd say "Half!? What's wrong with this thing?" So they'd keep it to themselves and realize that this will get us started, and as we get into the project we'll see that it's not enough and order more.
So all this asking them is a wasted exercise. We're not going to get any useful information from them. The product is like nothing they've ever delivered before - totally new. They're guessing just like we are. But by asking them we're delaying doing anything on the project for several days to get this useless bit of information. When you're putting something together for the first time you can't expect cookie-cutter answers. You have to use your experience, understanding of the problem, and goals and stick a finger in the air and guess.
If you're good, then your guess is pretty darn good, and you go from there. Asking someone else doesn't increase the confidence in your guess. Just do it.