As a general rule, most dealer body shops cost more vs regular body shops.
The at fault insurance company will either send you to one of their (preferred) body shop, have an appraiser come out and write a estimate, or they can take the estimate from the dealer that you got, and an appraiser will review it to see if the amount of damages that the shop claimed is in line with what they would owe.
Here are some facts you need to understand on damages. If you car is (X years old), then they may only pay for (used parts) vs new. They get the used parts from salvage yards of the same model/year that is (not) damaged.
Now if after the insurance agrees on the amount of the damages and (if) the amount is (less) than the dealer, then the dealer (if) they want your business, (should) agree to that amount, since you can take your vehicle to the shop of your choice.
But, as you state, you “might” do the repairs yourself vs a body shop and that is your choice, so insurance will pay you the (amount) of the estimate and if you do the repairs yourself, then in “effect” you will be saving the cost of labor that a body shop charges and that could be a lot of savings. .
Or, if you were to choose (not) to fix, then insurance issues you a check for the amount of the estimate, then you can cash it and spend it anyway you want and it is legal, since insurance owes for your damages and if you (choose) to drive a damaged car, they don’t care, and pay and close your claim.
Edit to Obi’s answer.
If you did not file a claim on (your) insurance, then your insurance will not be aware of this accident. Contrary to popular opinion, the (other) insurance company is not going to notify your insurance of this accident.
I read many times that other posters will state that the insurance companies talk to each other, but we don’t (unless) there is a dispute of fault of (who) is responsible or at fault for an accident, or only IF, we are going after the (other) insurance for repayment of what we pay for the damages and then want our money back.
But, if in the future you don’t fix, then when/if you have another accident and claim with (your) insurance, then any good appraiser or body shop can tell old damages from new, then they would find out, then they could dispute paying you for (any) new damages.
retired auto adjuster