As mentioned above, there are also costs after you do the initial application, such as doing occasional searches to see if anyone else is infringing your mark.

As mentioned above, there are also costs after you do the initial application, such as doing occasional searches to see if anyone else is infringing your mark. Also, if that search turns something up, maybe you can convince them yourself to stop doing it... if not then you spend $$$ on a lawyer and and there are more costs (which are then somewhat unpredictable ahead of time).