I doubt if anyone is really saving any money by using their own computer printers for printing name cards and letterheads.
Some print shops can do the artork for you but they are not really the best. You're best to find someone who is a commercial graphic artist. It migh cost you a little extra, but if you've got something good the first time round, you'll be saving in the long run.
How serious should I take a business contact who gives me his name card printed from a home computer? If you want to make the right impression, use a real print firm and make sure you get the right artwork.
Once you have found a good printer, give him all of your future work if you were satisfied. A good printer wants the same customers for a long time, and that is why they often offer special deals for start ups.
I'm sure you can get a start up package for a couple of hundred pounds, or a little more. Try to use two colours. If you don't have a logo, it's good to get one made. You can also use a photo. If you're not so handsome just use a stock photo of an image you would like to portray.
Never rush a print job. Take your time and get it done right.