The event you are planning may be a onetime affair or it may only occur once each year. It may be the only time you have booked entertainment for an event. Although the process may be unique for you, an experienced entertainer does events like yours all the time and knows how to make them a success. If not, they wouldn’t be in business. Look for acts that regularly perform at events of the type you are planning. Experience does matter.
That depends on your budget and the type of entertaining you are booking. The old adage is that "you get what you pay for" Before deciding what your entertainment budget will be, see what the act you would like to have charges. People will remember and talk about the entertainment for a long time. Many will not notice or care if some other budget items are diverted to entertainment to make the event a success.
Despite the general thought that for a performer to be good, they must be from out of the area, that is not necessarily the case. Many local performers will do a great job and can charge you less because they don’t have the extra travel expenses. Remember, the entertainer you are bringing in is a local act where he or she came from.