It all depends on what you are willing to spend ultimately. What is the condition of the rest of the car? Used engines are always available, a quick search on ebay will give you a rough idea of the price. Local junkyards are also another good option.
Are you able to preform any of the work yourself or would you need to have a shop do it? You can save a massive amount of money if you have the tools/time/place to undertake an engine swap.
I did one on my 1997 over last winter as a project, and it isn't difficult but requires time, patience, and above all a good, clean place to work.