Here’s a little research on this. Keep in mind that the cost of the two dominant products are sensitive to the price of fuel and susceptible to interruptions in the supply chain.
From a retail perspective I “googled” the shopping search engine for driveway sealant products. I got 27 separate products with the following breakdown:
Asphalt based: 19 products with 11 less than $20 per 5 gallon bucket with a low of $12 and an average of $20. It is important to realize the product variability here as well. Some have 1 year warranties, others have as much as 10 years with a cost range between $12 and $32 per bucket. That shows the difference in price, warranty with the quality of the ingredients.
Coal tar based: 5 products with a low of $12 and an average of $15 but all the available products are less than $20.
Gilsonite based (a special fossilized asphalt): 2 products with an average of $46
Acrylic based: 1 product for $42