What's going to be your furniture/style of room ultimately ? Don't answer that. The point being, do you need a recessed light(s), a flush light, pendant(s) or a chandelier ??? Until any room is finished and clearly defined what is the purpose of said room, only then will type of light (by you) be needed

Lighting is called jewellery for the home. I chose my own engagement ring with Hubby, I wouldn't let him choose for me, and we choose our own lighting too. I love lighting stores!

If you feel that your builder is taking advantage of you with pricing, I would at least handle the items that would be difficult to accomplish after move in. If you are building a two story house, definitely get all of your recessed lighting fixtures (through the builder) for your first floor as they are very difficult to install later on. For your second floor most electricians can go through the attic space. Do the same for any first floor locations you will need for any other fixtures such as fans, chandeliers (especially since they require heavier electrician boxes), etc. This way you will not need to cut drywall and beams in the future. For the balance, get the builder to supply their standards and replace them later on.

The benefit of using the builder for his upgraded fixtures is that the liability is on on them. For this they need to get compensated, so its understandable that you could get it cheaper.

It doesn't hurt to ask the builder if you could bring your own. I let my clients do that. If the fixtures they bring create additional labor, I pass the cost onto them. Of course we discuss this ahead of time.

Good luck.