Sounds good Are you not worried somone might read this and pinch your idea?
Also make sure you buy the components in bulk to get the best prices and advatise outside of eBay as well. Maybe a local Facebook selling group and get a website made. You can build your own website using one of those self build jobbies.
You could attend craft fairs and boot sales. Make sure you have some flyers with your website on.
I'll bet you will be able to shift them if it doesn't work out. Even if you had to sell them for cost price. Worst case scenario (IMHO) is that you would have spent your time, but broke even financially. You could google to see how much similar sets are retailing at and stealideas go from there.