Edit: There is one area that I have trouble with purchasing even with your reference guide: jewelry. Whereas on the other items you list, the "minimum" stats generally mean it's a good piece and the optional stats really are optional.
On jewelry, the bare minimum stats don't mean the item is any good at all, and the optional are basically required (or much higher stats than the minimum amounts you listed). Perhaps including recommended stats on jewelry could be helpful? This also applies to gloves, but less so, and much less to bracers but slightly.
I assume you're referring to the rares?
Unlike legendary, the rolls on rares are pretty random. I can only list out the main stats/affixes that you should be on the lookout for. Whatever optional or bonus stats/affixes you can pick up would largely be down to your luck + budget + supply.
Picking up an "optional" stat or affix on, say, the amulet, may sometimes cause the price to inflate 2x - 10x. You might find a dozen for sale at 500k one day and just one selling at 5m the next. Price is always in flux.
For example, the rare ring on my female Barbarian was a 3m purchase (there were 3 - 4 other comparable ones being sold at a similar price point). A week later, I can't even find one that is remotely close to it -- poorer ones were being sold in the 50m+ region. It took me 6 months before I finally got the upgrade that you see on my male Barbarian (which I also paid a measly 3m for).
If what I want isn't available or affordable, I'd check again later. Shopping for that right piece of rare will require a bit more patience.
This is what I generally do when I'm shopping for rares:
"OK, I have a 5m budget for an amulet. Let's see what we have meeting the minimum stats. Hmm, I see a lot of 1m amulets. Since I have a bigger budget, I'll see if I can get something better by narrowing down the list." *Adds an optional stat/affix or two and work from there*
In any case, I'll look into rewording the "optional" for the jewelries for the lower budget sets. Looking for a word that is not as strong as "recommended." Any ideas? Am open to suggestions for something short and sweet. :D
I'd be glad to build some example low budget sets. Should I omit crafted items?
Average crafts are fine. :)
I'd leave out BiS crafts since that would involve a lot of luck and/or a truck load of Demonic Essence.