Its not a hollow glass ball, they are sold as art glass marbles, they are made of Pyrex.
We have been in business out of our house for about 7 years now. You can take a % of the house off on the business based on the square footage used. We have a very good tax person.
Basically these would be for show cars. I have not seen any $29.95 shift knobs that look like these. IMO its like comparing a Earl Scheib paint job to an artist. Opinions are welcomed. I'm looking at this from a business point of view. Keep in mind there are people in the world that pay $200 for screen printed designer tee-shirts