I'm curious, do books have prices printed on them in the UK? Here in the US, the suggested retail price (pre-tax, obviously) is generally printed by the manufacturer on the back or inside the dust cover of every book.
Yes, books have RRP (recommended retail price). That price includes all taxes.
Gotcha. In the US, if you tried to keep that system, you’d need a different printed MSRP per tax nexus and books in warehouses would no longer be fungible.
Not really, that's just a manufacturer-recommended price for the seller to charge, the seller can put whatever they want on the actual price tag.