I use a sander, a knife and some sand paper for the finish. It's a lot of work, it'll take me 45 minutes to an hour just to make one. But, that is what makes this rocket special!
Thanks,
I am going to give you some tough advice here. Please think about this before making your decision. You are selling this kit for $15-20. That is right in the range for similar 3FN rocket kits from Estes and others. As far as I can tell there is nothing special about it. So, parts and packaging probably cost you $10. That leaves $5-10 in profit for the kit. Let's assume $10 to be generous. Paypal eats $0.90 off the top in fees so $9.10 total profit if sold for $20. It takes you 45 minutes to do a nosecone. I am going to guess you have about 15-30 minutes into the packing the kit and another 15 minutes in overhead talking to the customer and arranging shipping. So, you are making $9.10 in 1.5 hours. And that's not even taking into account additional hidden overhead costs. By the time you factor in returns, paperwork concerns, misc expenses, etc. I would think you would be lucky to break even even if you had enough to keep you busy full time for 40 hours.
Also, as a buyer of kits, I expect quality parts. A hand whittled nosecone with a cardboard coupler is half-assed in a my book and makes me question the quality of the entire kit. Why would I want to buy from you want I can buy a similar kit from say Fliskits for slightly cheaper and get a perfect machined turned balsa nose with it? Do yourself a favor and ditch the notion of making the parts yourself (unless you happen to have a 3D printer). The parts needed are available for decent prices in manageable quantities. That will bring your kit quality up and your labor invested down, which should raise your hourly rate to an acceptable level.
I highly encourage you to look at the thread where Dan Patel put together a new kit for sale: https://www.rocketryforum.com/showthread.php?140413-Mach-Buster-Rocket-Kit-Go-fast-on-a-budget! Study what parts he's offering as part of the kit, his pricing structure, intended market, packaging, how the kit is marketed. Figure out what your time per kit is and make sure your pricing can support a decent profit margin.