take a few to make your own RP. for a scant 3 weeks, a month at the most, you have a kilo min. for the cost of running a 220 tombstone welder on a boneash/charcoal/silica mix. Then heating the WP under vac, or in an argon aptmosphere for a couple days on the barby (gas, not kingsford)
Just flood the argon well while allowing the H2O to evap. and dump back into a bucket of H2O (warm/hot) to rinse out any unconverted P when finished. Rinse 3/4 times, VIOLA' RP
For lab grade, ya gotta do some work, but hey, only once if you make enuff...
clear head and a set of common sense/wits/sobriety is req.