You would not report this either as hobby income or Schedule C income, and you do not use the Business program for this.
After thinking about your question for a while longer, I realized you were talking about the sale of what the IRS considers a collectible. Collectible sales gains are taxed at a completely different tax rate and are reported as investment sales on Schedule D.
Given your high volume of transactions, you could break this down into one short-term and one long-term sale, based on whether you held the items less than or more than one year. Gain and loss sales can be added together within each category, leading to a net gain or loss on each category. Your date of purchase and sale would be Various.
[Edited 1:42 pm 1/10/18]
This short list of collectibles from Investopedia is useful:
What is a Collectible?
Providing the answer to this question won’t get us very far, since it’s simply “an item worth collecting.” A list of examples will give you a much better idea:
- Rare stamps
- Rare coins
- Rare books
- Art
- Baseball cards
- Glassware
- Antiques
- Fine wine
I will return shortly to add some links to Publications to support this answer.
I'm leaving my answer on response to an IRS notice because the IRS may still expect this income on a Schedule C and you would need to redirect them to the Schedule D.
https://taxmap.irs.gov/taxmap/pub17/p17-088.htm#TXMP51c36ea7
https://www.investopedia.com/articles/personal-finance/061715/how-are-collectibles-taxed.asp
http://1040return.com/collectibles-tax-collector/
