So many issues that come into play. I will address a few.
Myth #1. A bull with good EPD's is better than a bull with bad EPD's. EPD's are
predictions of genetic merit. People get excited about them and might make decisions on that basis. Just as important as the numbers is the accuracy of the numbers. Great numbers with low accuracy - you really don't know what you have yet. Young bulls generally have low accuracy EPD's. If the whole story were in EPD's, then no one would ever care what a bull looked like, just select for numbers. That is not a good plan. Now,
if all else is equal, pick the bull with good numbers. EPD's are not bad, but they are not the whole story. Certainly not the primary selection criteria.
Myth #2. Paying more money will get you a better bull. Or always purchase a higher priced bull. In the big overall picture, there is certainly a relationship. But, the people who buy your calves don't care what your bull cost or pay on that basis. Select and buy a bull that has the qualities you need for your cows and conditions and market. There are still unknowns until you get calves, but price is not the main selection criteria.
Myth #3. You need to use a purebred bull. Crossbred bulls sire calves that are not uniform. That eliminates sim-angus, balancer, beef master, Gert's, etc - all are crossbreeds. Many good calves are sired by crossbred bulls.
Myth #4. Use a young bull. Ship by five years old. Just like cows, keep and use a bull as long as they are doing their job with no signs of issues. It takes a while to prove a bull. Why ship him if he is proven and not showing any signs of problems or causing trouble? Just like a spouse, if they are working out, stick with them.
Myth #5. Never use a home raised bull. Always buy from a "breeder". If you have good cattle for your conditions and market, evaluate your retained bull calves the same as you would any other bull purchase. They may fit your conditions just fine.
Myth #6. Always buy a bull with a high weaning weight or yearling weight or the heaviest bull in the sale. Maybe from a performance bull test with ratings based on ADG and WDA. Tempting, isn't it. Those big fat bulls do look photogenic. Keep in mind that feedlot cattle are fed to a finish condition - not worried about longevity. You don't want a bull fed like a feedlot steer. If your friends are impressed with a fat bull, you need to get some new friends that better understand cattle. That fat is not muscle.
Just giving my thoughts for my area. And stirring the pot, hoping it don't boil over.