tried stitching up the taxpayer with a vastly inflated pricing structure.

Point of information: the gov.uk site is quite clear that the cost of a passport covers the cost of its issue. The cost is borne by the purchaser of the passport, not the taxpayer.

There are plenty of taxpayers without passports, and plenty of passport holders who earn so little their tax is small. The two groups - passport holders & taxpayers - are distinct.