There’s a few factors at play;

1) There’s customers who will pay 15k for the exact same users/features as you’re willing to pay <3k for. If they offered a cheap package then those customers wouldn’t pay for the expensive package.

2) Sub enterprise customers are a pain, they’re often as expensive as enterprise customers (acquisition, support, etc) but with significantly less revenue and higher churn. When a company decides where to focus it’s going to go where the money is.