It would be quite reasonable to impose a per-country charge based on the incremental cost of making products for that country, i.e. buying copies of non-free mandatory national standards, complying with these regulations, extra product testing services / approvals / bribes legally required to sell in a given market. It doesn't make sense for the customers who elected sensible governments to be paying more than their fair share to satisfy bizarre requests from the less-wisely-elected governments. You might want to offer a 10-year warranty (from date of purchase) on the PbSn version and a 6 month warranty (from date of manufacture, not purchase) on the RoHS version, until proven that this does not reflect the inherent reliability.
Chris