1) Buying a bar you will outgrow
The last thing you want to do is buy a bar you will quickly outgrow. For example, unless you have the funds to buy multiple bars, don’t empty your account on a training bar if you’ll soon need a “real” bar. Go for what you’ll need long term.
2) Buying a bar that can only do one thing
Many people believe all barbells are the same. This couldn’t be more inaccurate. The common mistake is to consider barbells with welded sleeves (immobile), bushing sleeves, and bearing sleeves similar. The fact is, a quality bearing barbell allows for the most versatility (power lifting, Olympic lifting, etc.). Then again, if you plan on strictly performing power lifts, the former(s) might serve as a better choice.
3) Buying without knowing what you need
This goes hand in hand with the above point. Before looking for a barbell, know what you want to use it for and make sure you’re digging for the right bar based on those goals. A bearing bar works great for most lifts but isn’t ideal for some. A welded/bolted sleeve bar is ok for some lifts but not most. It's also important to consider the ideal knurl aggressiveness/location, diameter of the bar itself, and coating/finish on the bar.
4) Buying a bar from an illegitimate company
Dishonest companies are sometimes hard to identify, which is why homework is necessary. Research unbiased reviews and speak directly with former customers if you can. If you catch wind of any unethical behavior/practice, walk away. There are several honest companies with high-quality barbells.
5) Trying to build your own bar
Don’t do it, period. There is far too much at stake when dealing with heavy weight to trust a “junkyard barbell”. We encourage creativity and innovation, but suggest leaving important things (like your life) to the experts. Saving a few bucks may not mean much if your homemade bar breaks overhead.
6) Buying a barbell without a warranty
In an effort to save money it’s sometimes tempting to grab the least expensive bar we can find. However, odds are good that unless you have a warranty, you’ll regret that initial savings while crying over a less-than-stellar barbell. Research what kind of warranty (not just 'guarantee') a bar has prior to buying.
7) Spending more than you need to
The cliché “you get what you pay for” often holds true. However, consider that many companies exploit this ideology. Perform diligent research and do a true apples-to-apples comparison between bars (quality, warranty, credibility, type, specs). Once you’re to that point then go for the lowest price.