Patio11’s argument is that most companies are charging a safe number that works, however that number is too low. By charging more, yes you will scare away some customers, but the customers who are concerned about price aren’t the customers you want.
In your case, say you cloned something like SendGrid and charged half the price. Their big customers like Airbnb or Uber effectively don’t care how much an email costs to send, they just want to guarantee that it is sent. So if you manage to score a customer like that, you are leaving a lot of money on the table.
On the other hand, the customers that do care about price are likely going to be lower quality, maybe they are sending bulk newsletters which if marked as spam will damage your company (as your IPs will end up on blacklists) - meaning more work, and more cost, cleaning up their mess.
I tend to think the mantra of charging more has gotten a little too popular and I suspect that many companies are now charging too much.
The big customers like Airbnb and Uber very much care how much it costs to send emails. The most price sensitive customers are the largest and they will try to screw you down on price much harder than smaller customers. When you are sending a billion emails the price per email is much more important than if you are sending a hundred.
Taking your example, there is no reason to think that charging less would result in more spammers using your service provided that you maintained equivalent quality controls. Spammers are probably the least price sensitive mass email customers as they are professionals who are most concerned about deliverability and ROI.
This goes both ways. You can definitely also increase net present value by pricing higher as long as value > price. Even better would be to create segmented/dynamic pricing that would maximize value capture up and down the demand curve.
If the market pricing is apparently so inefficient that a lot of potential value on the high end isn’t being captured (in economics speak we call this the consumer surplus), then this means there is also potential for arbitrage on the high end. Clone any service and charge 4X!
Probably a more useful approach to take is for the original service to do this - set up your own competitors and see where the customers go. This approach is pretty common in the non-SAAS world.
In my personal experience, I once chose a host for a game server for my friend group because it was by far the cheapest option. However, one day with only a couple hours warning the host shut down. I didn't even have a chance to download a backup. Had I been running a for-profit server, my entire business would have vanished overnight and choosing the cheapest option would have shot me in the foot. Often paying more is worth the guarantee that stuff you depend on won't vanish overnight.
I have often wondered if there was a business in just feature copying a well known SAAS business and selling at exactly 50% the price. The selling pitch would be "identical product, but half the cost because we don’t have the massive SV overheads." I have seen quite a few examples of this in practice, but none where it is blatantly stated.