They can be wildly expensive, and some truly aren’t worth it. I almost always opt to donate the shirt I get because frankly I’m a little picky about my gear and they’re rarely good quality, but even beyond that I’ve run a few where the race coordinators just haven’t got a clue how to host a race and I really start to question why I even paid to register at all.
Fortunately I’ve found an amazing local company that hosts trail runs and is managed by a former ultramarathoner and they’re the best races I’ve been a part of. I also feel good about paying a local small business.