In my experience, with bibs - much moreso than any other single piece of gear- you truly get what you pay for. It took me only a decade of riding (okay, and a well-paying job) to catch on, but good bibs are absolutely worth paying for.
I steadfastly disagree to only shop sales and never pay full price. Not that you can't find good deals, but it's the wrong mentality to only search deals for something that actually works for you. It's only your prostate health and equipment functionality on the line, you know.
My advice is to try bibs (never shorts) that are designed for 20-30+ weekly hours in the saddle, find what works, and put your own value on it. I used to ride $90 - $150 PI shorts or bibs. Now I've relegated them all to spin class or <2 hr. MTB rides.
My current favorite kits are the Rapha Pro Team and Attaquer Race - both are very compressive and form-fitting with a chamois that's good to go for 8+ hours at a time. I don't know if it's perception or science, but I feel the added compression keeps my legs fresher during long or hard efforts.