A3 is a big sheet of paper! Quality laser printers of this size tend to be between �2000 and �5000 so I think you'll struggle to find one sub �1000. If you do then quality may be suspect. Do you really need a laser of this size? Part of the reason they're so expensive is that not too many are sold compared to A4. For occasional use you may find a second hand A3 inkjet or plotter for around �200. Try ebay.co.uk.