Retail prices in the US segment are the highest in this niche, and so is what the buyer expects in return. They read the guarantee window before the price, they ask what happens when a count drops, and they judge a seller by whether the order page tells them the truth. None of that is solved by owning a script - it is solved by the storefront, the wording in it and the automation behind the order.
Which is the argument for renting rather than buying. A bought engine asks for a licence, a server and a flat monthly fee before the first order exists. Renting bills by volume: up to 100 orders a month is free, orders that go through our own provider are never counted at all, and servers, updates, certificates and backups stay on our side. What you spend your time on is pricing, guarantees and customers.
The dollar needs no special handling here either. USD is the panel's native currency, which means no conversion layer between the provider's price and what your customer sees, and no rate drift to explain when a count was quoted last week.