Great Question.  I found an article at https://adage.com/article/data...

that covers advertising by SIC codes. As you can see, it varies from less than a percent to over 20 percent of sales.  I once had a client in the retail rent-to-own business (televisions, furniture) that spent $2,000 per month, per store regardless of the size of the store or the city it was located in. For some stores, it was hard to spend that kind of money. For others, it was just a drop in the advertising budget. Still, he grew from 10 stores to 550 in just five and a half years, so he must have been ding something right.

Try to get a take on how much money stores or businesses like yours are spending.  Stangely enough that $2,000 per month budget I mentioned is pretty common in rent-to-own stores.