If you pay US taxes and want to claim your donation / subscription to the WPM as a tax deduction you are allowed to do so, on your own say-so, up to a limit of $250 per year. If your donation exceeds this amount in any given year, you need a written receipt from us for that amount. Please email firstname.lastname@example.org if you need one. Our EIN number, if required, is 56-2125524. Whether you make a deduction from your claim to allow for any monetary value of member benefits is essentially a matter between you and the IRS. A reasonable case can be made that these further the charitable purposes of the organization, and are thus not a quid pro quo.
Tax deductible status is so far available only in the USA, though we hope to extend this to the UK and later to other countries, as and when numbers or other considerations make this worthwhile.