I think cycling kit need not be expensive but it should be "good enough". Like anything, if you buy the cheapest off amazon or some such you will probably get poor quality control. This pertains to material, zipper strength, pad material etc... After a certain point however, there is a law of diminishing returns in which you are paying for brand or perceived performance.
A salesman once commented (in regards to buying bibs): "You should spend $50 per hour of intended riding." I laughed as at that time I was ramping up to 12 hour rides.
I don't run out to buy super expensive kit, sometimes I file it and keep my eyes open. Once I saw a lightweight (cuban fiber I think) shell jacket that I liked but was being sold for $400. Although I liked the weight and folded size of the shell I couldn't justify the cost. later, while poking around in a thrift store I found a similar cycling jacket (nylon but still light and very compressible) in like new condition for $10. That thing worked perfectly and has seen a lot of service both cycling and trail running.