Selling an item received free with purchase of something else

I bought a dishwasher this year while the manufacturer had a promotion of "buy a dishwasher and get a free coffee maker." I had to buy the dishwasher first, then send in the proof of purchase info, and then they sent me the coffee maker. I promptly sold the coffee maker on eBay. 

 

For the purpose of capital gains, what is the basis of the coffee maker? 

 

I spent $1506 on the purchase. The coffee maker's retail price is $1399 (although it sells on Amazon for more like $800). I sold the coffee maker for $528 after seller fees and shipping.

 

In my mind, the $1506 purchase price was the cost of 2 appliances. But I don't know if I need to treat it as if it were a $1506 dishwasher and a $0 coffee maker, in which case I would have to pay short term capital gains on the $528?