I've raced for 15 years, had 3 sponsorships (2 still active) and currently have a trf415msxx and a ta05, so yes i'm aware of the grade of cars we race with, but the saying highlights how seriously (bordering on too seriously?) how some people take the hobby - not everyone into r/c will be.
You have to have a need to race, or there is no point in doing it.
All i'm highlighting is be
realistic
Understand where your limits are - i've done what i've wanted to in this hobby, I have nothing else to prove to myself, or others. There is a point where you will cut yourself off at, wether it be at going to the bigger events, ones far away from your home town, or the cost -or all of those.
i'd never tell anyone to sell up - but if they are not enjoying it, i'd tell them to ask themselves why, because no one comes back for a second punch in the face unless they feel they have a chance of "winning" what they want from the hobby.