what do you think is a fair price for a high quality ebook?

Difficult question to answer. But, I can say this. If I am on Amazon, around $10-00. If buying from an expert on their own site, more than $10-00 is just fine (even much higher, like $99). I am not certain why, but I think I am happy paying a higher price to an expert that I have been referred to or have read some emails - they just seem more credible.

What your market is willing to pay for it. This might not seem helpful at a first glance, but that is always what it comes down to, no matter what product or service you are selling.

its more about what they can make from the contents of the ebook. If it's knowledge- and resource-packed, that would take a lot of time to find or discover otherwise, then you can def upcharge accordingly and it would be a fair price.

key aspects being - info not (easily) available elsewhere, pitched and targeted to readers who are actively seeking the solutions you talk about (they're in the sales window), and reviews/testimonials of others talking about how this helped them.

we did a real estate industry focused one which had 1700+ purchases at $80 each, and another one for the securities investment folks who paid $700 for that.

so "fair price" depends on the info, industry, buyer.

It's a bit like asking "what is the right price for a SaaS?"

The "SaaS" part, or ebook in your case, is just the format. Ultimately it's the value to the customer, their budget, and the competitive landscape that determine the right price.

I recommend checking the pricing of books targeting similar audiences. It doesn't mean their prices are correct, but if the author/publisher seems legit it might be a good starting point.