£500 will get you a 16v that needs some TCL, possibly tax and/or MOT and a good service. £1000 will get you something decent, with a few months tax and MOT, some mods maybe, some rust maybe. Give or take £200 for this.
£1200+ will get you a good 16v, with relatively low miles (100,000 or less is low), no rust/little rust, MOT and tax and some mods maybe. Anything above £2000 is too much to be honest, unless it's a real minter with low miles and an anniversary edition.
£1200+ is VR6 territory, for a decent well taken care of VR6.