Money isn't the reason customers aren't buying your product.
$15 or even $150 a month isn't that expensive for a company to buy.
The real reason customers don't buy your product is probably that they don't get it. Once they understand the value and they are convinced that this either saves/makes them more money than the price, they'll pay! It's a no-brainer. So the first thing you should do when people don't buy your awesome app isn't lower the price but find a better way to convey the value.
The second reason (equally important as the first one) customers don't buy isn't also the price. It's the psychological anxiety and uncertainty customers feel when considering your product.
"I have to persuade my reluctant CEO." "I have to train my teammates and try to get them to use the app." "I have to migrate all our data." "What if we migrate and turns out this app doesn't have that feature we needed?"
These concerns don't necessarily translate into money per se. So, you shouldn't try to A/B test your pricing but instead talk to your prospects. Listen to their concerns and address them.
And all that is to say, without sales + direct conversations with the customers, you will have no idea why people aren't buying your product.