Actually there is no simple answer. One has to keep open mind and research on what one wants to buy, to valuate the pros and cons.
I got reverse cam for XUV 500 from dealer for 4k. VFM
since I could have peace with warranty and great Fit & Finish. On the other hand, Roof rack was priced at dealer as 13k, Which I brought for 6.5K from Decor shop. Same issues with items like HID kits, Speakers etc. Horribly priced and not enough expertise to install them either.
Name of Dealer- Mahindra, Jalgaon
Brand Name- Mahindra
Purchased Car Or Bike- XUV 500
Kind of Accessory Bought- Reverse camera
Price Quoted by Dealer- 4k
Price of Similar Equipment Outside Dealership- Same