It doesn't need to be a lot of detail, or precise. Even just a "from $..." or "plans starting at ..." would be enough.
* I know that I will forget I even clicked on that link. The page has 3.5 seconds to convince me to stay longer.
* I'm mildly intrigued and form, in my head, a price I'd be willing to pay for the product.
* I scan the navbar for a pricing link to see if my expectation matches reality. I find nothing.
* The site obviously doesn't value my time, so why should I stay?
It's disrespectful.
Second, the other saying is if you have to ask how much it costs, you can’t afford it. So by concealing the price, the company is telling me the cost is too high and they know it. They are telegraphing that part of their sales process requires a salesperson to coerce the money out of me.
Also, note that we don't actually require (or even ask for) email addresses or anything personal when you install the browser plugin. You just click install, try it for 2 weeks, and then buy if you want. The standard pricing is $2/mo, with a discount for annual purchase.
I totally appreciate the feedback and will see how we can better communicate our pricing to alleviate concerns like this.