The vast majority of traders are not VAT registered, but the terms and conditions of the site make it very clear that the contract is with the vendor, not the collective, and each vendor has their own terms and conditions etc on their own shop.
At no time does any cash come to the collective, it all goes direct to the individual vendor via their own PayPal arrangement. The collective is a not for profit organisation.
If a vendor is VAT registered then the prices on their shop display that the price is inclusive of VAT. If they are not then it doesn't!
I thought of the 'Contact Us' idea for overseas orders, maybe using PayPal email invoices as an option?
What about customs and excise in the country that the vendor delivers to? Would the purchaser have to declare the goods and pay local taxes? Is that the customers responsibility?
Thanks for your input. Much appreciated.