There is one piece I really went all out on, and I do not regret it.
Less expensive alternatives may protect as well or better. This one, although pretty pricy at $260, looked flexible and comfortable. I knew if I bought something that limited my mobility, eventually I would stop wearing it.
You may not need equipment like this, it depends on how and where you ride. I see this vest not just as a measure against falling, but also cars.
The larger point I'd like to make is that with any piece of gear, you won't regret spending the money on something that is comfortable. If your cheap knee pads dig into your shins, even a little or only while turning, you could tough it out and save a buck. Or, you could spend the extra money and never let that be a nuisance to your otherwise (very freakin) enjoyable experience.
That said, protection is priority. Medical bills can be WAY more expensive than even the most expensive gear (Full body airbag suit $1100), and you can't put a price on a lifelong injury.
Oh, and these knee/shin guards. Worth it at twice the price, guaranteed to make you feel like RoboCop.
Ride safe, ride far.