The starter level tier is great for really tiny shops. But there's a huge market for a subscription tier that affords more than 50 shipments/month but not as many as 500 for the next level.
Something in the range of 150-200 would be wonderful. I'd gladly pay $19.99/mo for such a tier. Especially since some months we're way under 50, but sometimes we might ship 100+ and it makes ZERO sense to pay too much, or be cut off part way through the month.
I do also have an EasyPost account that I used before switching to ShipStation. One option is to re-incorporate that integration with our eCom solution when I run out of shipments with ShipStation, but that's a less than desirable solution.
ShipStation, if you're listening, please consider this missed market opportunity!