The shop vice is one of the least understood tools which people own. A vice needs to be set up and used properly. There are several different methods for attaching different jaws. The method most in use seems to be to get some aluminum plate or angle iron, bend them into shape and drop them over the existing hard jaws the vice is supplied with. A better and seldom encountered method is to make up jaws of several different materials from wood to plastic or different metals like aluminum or brass and even rubber glued to a plate. Drill appropriate countersunk hole in them to locate the mounting screws that come with the vice face plates and use whichever face plate is appropriate for the job. I have seen a couple that were cast around a specific piece with acra glas and separated by plastic shim stock. Those were obviously special purpose face plates but they certainly did a great job.
Most vices have play in them. This can cause movement that will damage whatever is being clamped. Also, most hobbyists and even some trades people just use one type of vice in the shape of a large cast iron clamp that his mounted with bolts to a bench. It is a good start.
A well equipped shop, used by someone that likes their tools to do what they are designed for will have up to four and maybe even more different vices for different applications. I have several. A large 6in heavy jaw vice, a wood workers vice that comes in very handy for other things as well as wood, a micro vice for holding small trigger parts for honing, a pin vice, a loose three inch jaw vice that can be moved around for better access on the bench, different vices for the milling machine and drill press and a small portable 2in Record vice that will clamp to the edge of a table. I also have a 1inch Record vice that is attached to a piece of flat Delrin that is hanging on the wall above the work bench and can be clamped into the 6 in vice for a very secure base that magnifies the usefulness of the small vice. There is also a Card holding vice. Most used for electrical control cards but often very handy for layout work. There is also a suction cup mounted rubber jawed vice which has only proven to be useful once. It was one of those Princess Auto things that was cheap and caught my eye in a weak moment.
Just remember, a vice is a tool for holding things. It has to be fitted to what you want to hold or a lot of damage can be done to the piece you are working on.
I also have a couple of barrel vices and several fly tying vices. The vice needs to be versatile and strong. Be careful with some of the Chinese knockoffs, they are often brittle or have casting flaws which cause them to break easily, also their screws are often to soft or poorly attached to the handles.
What you intend to attach the vice to is very important as well. I'm lucky and have an all steel home built and welded together steel vice with a 5/8 inch thick, 30 inch by 60 inch top. I don't like clutter under the bench. The clutter is a good place to lose parts and gather the detritus such as chips, sawdust, filings bits of scrap etc. The bench is just as important as the vice and should be chosen accordingly.
All that being said, beggars can't always be choosers and just go for the best vice you can find and build up from there. Put an ad in the local paper stating your requirements for a vice. Often people are just looking to get rid of them. A weekend at garage sales or an evening at an auction house can also yield some of the better made Swedish and English vices at very reasonable prices. Some of the vice coming out of the former Soviet satellite countries are also reasonably priced and of very good quality. I don't think vices are even made in England any more.