Ok, working backwards: if you're charging a fixed price, follow the advice I gave earlier; if it's PWYW but with a suggested price, the suggested price should be about 70% of the price that you worked out as above, but preferably don't have a suggested price at all, because otherwise it kind of goes against the whole idea of PWYW; if it's free, don't have a suggested price at all, because otherwise it's not really free (see above).
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