What are some of the limitations of dbt ?

dbt doesn't do much automation/ETL outside of the database you're working in, as other tools might be able to.

That being said, it's very powerful, I love it

eBay also provides a similar service. How is this any different ?

http://sellforme.ebay.com/

On that page I readily see significant differences between the two. I'd prefer The Deal Truck if it were in my area.

the headline on HN is about selling furniture

sellforme explicitly lists furniture as something they do not sell. Or any other item over 25 pounds...