We supply our own phones but are given a strictly enforced "allowance" (all recorded as benefits for tax etc)
The company benefited from this by getting cheap SIM only deals, not having to arrange backup phones and having 24/7 access to us.
I've not worked out who has got the best deal out of the arrangement over the years, it's just having to stump up £300 to buy the PAC doesn't seem right
After all you can get "full monty" SIMS for £140 per year !