i imagine something like this:
prompt> checkprice
price of foo is 42$
prompt>
To run multiple commands.
Something like:
while(true) {
Console.Write("prompt>");
var command = Console.ReadLine();
if (command == "command1") doSomething();
else if (command == "command2") doSomethingElse();
...
else if (command == "quit") break;
}