I have 1 armored jacket and one pair of armored pants.
They are both
Olympia and are about 5 years old with around 80k miles on them. They are still in excellent condition. I've ridden in just about every imaginable weather condition with them. The jacket is the Airglide and the pants are the Airglide Overpants.
I wear them all year and only vary what liners I place inside them. Although the included liners are waterproof, I prefer a rain suit over my gear.
The gear is well vented in the summer and the overpants with their full leg zippers are VERY easy to wear over jeans, slacks, or (for a cooler option in the summer) shorts. I can easily throw the pants over my dress slacks/suit pants and not worry about them getting dirty.
With the insulated liners, the jacket and pants are quite warm and with heated liners inside that, I've ridden comfortably down to 0F. The jacket and pants have very good reflective material and plenty of pockets for storage. The gear include CE armor in all the right places. A very flexible, long lasting, quality product.
I don't know if these would qualify as "low cost" since together they will run you about $520. But this is a set of gear that you'll only need one of and will last you a very long time.
Olympia has many many different styles and colors (also available in women's cut). My wife has the women's version of the airglide are really likes it. Here are the current version airglide product.
Are all of these pants considered overpants that can be worn over jeans?