If you are in the US, and close to a Trader Joe's you can get either black or red "caviar" for $1.99 a jar(really whitefish and salmon)--quite good, and generally well received--one friend, an insufferable food snob, praised it to the heavens, and pointed out that cheap caviar is not even worth serving!

If you are a stickler, and want the flavor of real sturgeon caviar, at less expense, try pressed caviar, which is actually less salty, an more tasty, but not as nice looking--but be prepared to pay a bit more than $1.99!

Traditionally, caviar is served spread on really thin slices of buttered black bread--but it also works well if you set the caviar out with a variety of crackers, toasts, and, the bread--I inherited a cut glass fish(to hold crushed ice) with a wee glass-lined silver bowl for the caviar--it is equally effective if you just stick the jar in a bowl of ice--

Set out a plate with cucumber slices, red onion, slivers of lemon, and such items from above as you might like--some people even like it on wedges of cheese--

I also start out with a tray of caviar on crackers and make a fuss about offering it to everyone individually--that way, people who haven't had it before tend to try it, and, often, like it--that way, you don't end up with it sitting out on a counter untouched--

You really should serve it with Champagne, or at least the vodka--beer takes the romance out of it--