Guzz2K: You are far better off just getting a printer that is good enough for proofs, test runs and proposals, and going to an outside agency for quality prints. You'll save money, you'll save time and you'll save hassle. Most print shops will take short runs or even one-off prints of posters and so on. Last time I had to print my folio for a graphic design job, I went to a print-shop and spent around $15 for 10 copies at excellent quality on great paper. A friend also printed one, and only one, poster of an artwork he had completed at A0 size for around the same amount.
Nowadays, I keep an inkjet printer in the cupboard for those times when I need a printed record of something, and anything else I take to my local printer.
Another bonus is that your hundreds of bucks will be going to a local business rather than to a multi-national printer manufacturer. Plus, you don't have to worry about breakdowns, driver problems, maintenance, cleaning and so on. And lastly, you'll always be able to print at any size, on any paper, for any purpose.