progamming

Hellow my genesis g80 2017 Dont switch start just turn on light or audio all just dont start engine in dashbord display not key detection ?

We lost one of the smartkey keyfob/remotes for our 2009 Genesis. The dealer is telling me $315 for a replacement one. Ouch. Another dealer quoted me $275, plus $14 to cut the key inside the remote. Used ones are on eBay for much less. If I buy a used one, and then take it to the dealer...