I'm a bit like you, I prefer published list prices. It really helps me if I know my budget is somewhere near your list price.
But I'm also in a business where we don't. And the reason we don't is because hardware is involved, and so prices can vary by 2 to 3 orders of magnitude.
In other words it takes time to gather up your requirements, which include hardware, software and crucially install and support services. From this we can generate a quote.
I'm not involved in the sales side, but I expect there's at least some demo as part of this process because it's helpful when reading the quote if the user has some idea of what they are buying. I don't think it's a terribly long demo though.
That all said, it is helpful to both parties if budget is mentioned early. With software-only projects I will often give the caller some idea of budget very early just to make sure we're playing in the same ballpark. That saves a lot of time.