I see that MowDirect are offering the Mountfield HP180 45cm petrol lawnmower fitted with Briggs & Stratton 450 Series 148cc engine for just £199.
MowDirect also have the self propelled version of the same mower, the Mountfield SP180, for £249.
They both have a 45cm (18″) cutting width, five cutting heights and a 55 Litre grass collector.