How can you provide this as a free service for collectors? What is your business model?

Our Verified Buyer service is always free for buyers/collectors. We may charge sellers a small fee (sellers have the regulatory obligation not buyers). Our fees per transaction for sellers range from free to a maximum of £50 (equals half a percent of the sales value) for standard transactions. (Non-standard transactions may include sales over £1 m or from buyers from outside UK, US, EU, Switzerland, Australia and NZ).