Your profit appears pretty marginal. One thing, I have heard there is a pretty high cull rate on those cheap blanks. Cull 20-30% of them and have some come back due to missing one that should have been culled now and then and your profit disappears. Looking at assembly, handling and such I don't think you can turn a reasonable profit at $169 or even break even. It is an awkward price point for sales too. Might as well make it $189 or $199, sales would be almost exactly the same, net would jump a lot.
I do like carbon fiber and would buy one or two shafts under $200 if the taper profile suited me. The five and six hundred dollar shafts strike me as ridiculously overpriced. On the other hand, wooden shafts that were ridiculously underpriced a few decades ago are riding the price increases of shafts overall and are getting fair market value or above in many instances now. No more fifty dollar shafts for the most part. No doubt somebody in a backyard will make them for that, nobody making a living from cue building is likely to without there being a special reason to.
I would buy one more carbon fiber shaft that suited me for up to $300. Price wouldn't influence my decision to buy or not buy below that. Six and seven hundred dollar shafts seem a bit over the top to me. R&D to get back for some entities but I don't think that took long for most. My price points I have now are based on being a hobby player. Back when I gambled nightly if others accepted the shaft as not marking me I would pay for the one that suited me best, cost not an issue. Racing cars I paid a lot of money for a tenth of a second sometimes. Same with competition guns, price wasn't the major factor. I did gamble nightly for ten years playing off the wall with a hinged cue or three laying around the house. I gave away over a dozen cues in the seventies and eighties, some valuable cues. I didn't want to be marked as a serious player although it was unavoidable over time.
That does raise the question, does your market for a $169 shaft feel the need for one? Internet research is a chancy thing at best. Open up a chance for preorders with a small deposit and guarantee full refunds if you don't make it to market within a year. See how many are willing to plunk down a thirty or forty dollar deposit once you reveal the profile of the shafts. Money talks and BS walks, and sometimes as many as 90% of would be buyers are just tire kickers when it comes time to put down cash.
Good luck if you decide to take this past the daydreaming stage. I would go with not less than 35% mark-up after material and labor. That seems generous but can disappear in a hurry!
Hu