I find that generally, maintenance (usually oil/filter changes) packages cost about the same as having the work done by the dealership. I can't speak for the C8 but that's what I found for the last car I bought new. It depends. I'd suggest you see what's included and compare it to the normal cost of same. To figure out the servicing you'll likely do, keep in mind how many miles you'll put on the car if you park it for some of the year. As well, find out the cost of an oil change if you supply the oil. That can save you a ton since you can usually buy the same oil from a Mobil distributor in your area, far cheaper than the dealership price. Or if you really want to get adventurous, buy the OEM oil filter (and DCT filter for that matter) at a discount from a GM wholesaler and supply those plus fluids to your dealership. Also decide if you're able to do any of the maintenance that's included in the package, yourself. Finally, see if purchasing the package allows you to have the work done at any GM dealership. If not and it has to be done where you make the purchase, make sure you're pleased with this dealer's service or if you don't know from personal experience, check out its Web reviews and ask around. Good luck!