I bought an inexpensive sissy bar/luggage rack combo a few months ago.
No problems so far. The instructions were laughable and I had to run down a few bolts but it's held up just fine, including being loaded up for two weekend camping trips to date. Not a long history, I know, but I haven't regretted the purchase yet.
Still, you are going to get what you pay for.
The construction seems robust, the finish is OK, a little rough in places, but nothing I can't live with...especially at the savings. The chrome is thin...you'll have to keep after it. My bike lives outdoors, so I have to keep after everything.
If it ever needs re-chromed at some point, I'd still be way ahead of the game. Heck, I could totally replace the whole thing new about three times over before I reach the cost of some of the combos out there.
It's in my signature pic...