Finding a good vise at an affordable price is usually possible by watching estate and garage sale ads for mention of "tools" and searching Craigslist or Facebook Marketplace for "vise" and "vice" because of spelling variations. Another hint is to know that there are certain good brands that don't get respect. Almost everyone knows a Wilton is valuable, and Craftsman vises also demand a premium. Rock Island and Reed are excellent, and not quite as valued, but still not cheap. Morgan and the heavier Columbian vises don't get the respect they deserve and are often underpriced. The smaller, consumer grade Columbians are among the better vises of that grade, but are not designed for heavy use. If you are looking at a Prentiss, check out the back end of the slide, which is prone to cracking. Parker is an excellent brand, but can be priced high, along with Athol (which was branded Starrett later) which made excellent vises.
Since you now have a vise to work with, take your time and look for bargains!