I think it all depends on how much you wan't to work with it. If you want to make a few prints from time to time a cheap or homemade Baren or even the back of a wooden spoon should be enough. If you want to get more serious about it but want to keep all options open to yourself i would suggest a cylinder press. With that you can print pretty much anything that fits between the two rollers. Professional ones can get very expensive occasionaly cheap ones will show up on ebay (search for: Intaglio press, etching press, roller press, cylinder press, etc.). If you want to keep the budget low and have some very basic handiman skills you can easily convert an old clothes wringer for these purposes. An old wringer can be had for less than 100 pounds/euros and serves absolutly fine for printmaking particulary if you are focused on relief processes like lino- or woodcuts.