I had to look up A3 and A4 as I wasn't sure what sizes they were. My printer prints larger than A3 but smaller then A2(13 inches wide x infinite long). Epson Stylus with pigment inks. It was a big investment, but I got it with a $150 rebate. I've yet to sell enough prints to pay for it... and I'd already like to get something that will print even bigger...
I both love and hate my printer. I love the freedom of running off a print as soon as someone orders, of being able to choose my own papers, having full control of the process from start to finish, and I love the thrill of seeing an amazing print coming out of the printer(I still squeal sometimes!).
On the downside you have to figure in cost of printer, cost of paper, cost of ink, cost of wear and tear on the printer. Also you have to swallow the loss on any mistakes - if you put the paper wrong side up, if the paper is slightly crooked, etc(if you outsource they have to replace any mistakes). You have to know what your backup plan is if your printer stops working while you're in the middle of fulfilling an order. Also, if you're not familiar with color management, calibration, etc, it can be a bit of a pain to get the prints you want out of your printer.
Even with all the drawbacks, I wouldn't give up my printer and go back to outsourcing, but I know it's not the best option for everyone.