Yes you're right. But most people aren't aware of that. And even if they are they will be put off by committing to a transaction to see if they like it or not...
If it was free and it looked really good, then I started playing about with the options only to find I had to pay for being able to customise it then I would happily pay twice what you're charging.
It's always hard to get the balance right. But if you want people to pay before they use then you have to rely on exceptional marketing. Better to let users experience a portion of what you've created before asking them for money.