not true, I learned and read a little on my own and was able to register my trademark in the US for a couple hundred bucks.
Get the .com version. Start building the site. Once it gets decent traffic and before it gets popular, then start investing on trademark and other extensions.
Just my 2 cents.
From my personal experience, I worried too much on how to protect my brand and bought the domain for 10 years, bought the .net, .org extensions and after 5 years I got rid of them.
So dont waste your money on protecting your domain name in other extensions UNLESS its a very unique, premium name. Consider lower cost and saving money an additional income!
Dont let the excitement of your first buy convince you that you need to buy more and more. Invest your time in actually building your site before you make the mistake of buying 50 domains like myself. Finally, I took the loss and got rid of many of them. It took me 5 years to finally admit my loss! ;(
Its kinda like buying stocks and holding on to them hoping the price goes back up.
Best of luck! :)