problem with 2003 CTS brake lights

Hi, i was wondering if anyone could help with this problem.. i have a 2003 CTS with about 130k kms on it.. recently, i noticed that rear left brake light doesnt work anymore, along with the horizontal brake light that's on the trunk.. the dealer said the regular brake light doesnt cost much since it's just a bulb.. but the horizontal one will cost me around $750 because it's not just a bulb, but the entire light assembly.. am i being taken for a ride here? please help!
 
thanks in advance!

try this www.ledfex.com

thanks, but the website is actually ledfix :)
it seems that it does come in a kit, but the item is sold out.. it doesnt have the prices either