I've been looking for an edge to edge (no white borders) A3 printer for a while and this fitted the bill on an unbelievable budget. The box is deceivingly large - it's a big printer but for an A3 is pretty compact. Great reviews online and a fairly speedy printer.
This model is reduced from £150 to £75 with £25 cashback (paid within 6 weeks - check link on Web to see how to claim) direct from HP and 3 year warranty. Altogether £50 so 66% off.
Not currently available for delivery but this isn't too much of a goose chase as was available in 2/3 nearest stores in Derby and doing a few more town searches was available 50% of what I viewed.
As commented, same price and available for delivery at John Lewis, or Staples price match plus 10% off in store. Cashback is direct from HP so not store specific.
As for needing this, I'm a design student and as any design student will find out A3 becomes vital. Having edge to edge will save me a small fortune on using professional printers to create portfolio work. This also means it is great for home photo printing and reviews state colours print well for this use.
4 seperate inks, meaning no wasted colour cartridges. Scanner (midway between A4 and A3 size), fax (not for me but great bonus if you need it) and wireless, touchscreen and mobile/tablet app printing to name but a few of the features - please read full spec.
Using HP original inks (XL cartridges give a much better yield) the printing price for A4 colour is 4.9p including 0.7p paper cost.