I don't think he's saying to be afraid to talk to people. Often when I'm making purchases for my job though I'll run into a product that doesn't show any pricing and says to contact their sales staff if you are interested in making a purchase. I hate that and will pretty much always pass them over for a site that doesn't force me to contact them and doesn't restrict my purchase options.
If I can see pricing and purchase at any time but I still have questions, sure I'll contact them. But don't force me to.
In my previous company we had a solution that cost $1000/mo. When we advertised it on the website - we had virtually no signups at all. When we removed it - some people start contacting us and some of them were converted into customers.
When you don't see the price - in most cases that means that this solution is strictly B2B, so you're not their target market.
If I can see pricing and purchase at any time but I still have questions, sure I'll contact them. But don't force me to.