Best place to buy a bike is a shop you trust and will want to build a relationship with.

If that describes this place where you want to buy the bike, make it clear. Tell them that you are planning to buy more stuff. List that stuff. Then ask politely whether they can make you a better deal if you buy all the stuff at once from them.

You'll probably find that they will offer you some kind of discount on accessories purchased with the bike, but not so much on the bike itself.

Try it and report how you do.