Why should the client be paying for a service they're providing to you?
More importantly, how can they stay in business if they cover the costs your business creates for them?
Half does sound like a lot; you should look into the account fee structure and see if you're missing something, like if there's a minimum per purchase, or some settings that could be changed.
Your other options include raising your prices, as you've mentioned (which is what most businesses do, to cover the costs of licenses and tax fees - they need to make income on top of those, so the prices are raised to cover for them), or selling on a platform like Steam, which allows regional price differences.