VRCT is £30.00 (since August 2007)
VRC is £45.00 Initial application then £25.00 for renewal.

Note: VRC is the Voluntary Registration Council (google it)

I would expect a statutory Register to charge all Registrants the same whether on VRCT or not eg. if you renew your VRCT (£30) and a couple of months later the "actual" Register goes live, you would sill pay the full amount.
i think it naive and misleading to see VRCT as a "no claims protection" against the full price of statutory Regulation.