The inset LED strip look is very common in cabinetry today. If that's not something he regularly does, then yes, I can see a learning curve with extra time given to it costing that much. He may also be figuring in the cost of a change order at this point as well as the possibility of having to remake the shelving if you don't like it. It's sometimes recommended to put trim on a shelf like that to help prevent sagging anyway. If you have crown or other trim you can even wrap molding to match around all the sides and have a more shaped shelf if you like that look.

$200 is reasonable for a change order.

@hallett - can you provide a bit more context as to why?

IMO we don't have a reason if you want it done you pay the price. I have no idea where you live what the situation is and seems fair to me . I think the edge on the front gives the illusion of a much thicker shelf which I think will look more expensive.I think there is a risk of damaging a shelf that is not thick enough for what you want.

The $200 sounds fair because what you want will take more time and hassle and more time equals more money.

Thanks for the dialogue.

I would agree if this was a design change from the original. But original scope says two solid wood floating shelves at 2.5” thick, 12” deep, 42” wide. I read that as a single block of wood. Having the edging was not specified upfront. I don’t see this as a change order. Do I have a leg to stand on?

$200 seems nominal but this is one of many examples of a bait and switch that inevitably comes with additional costs.

If you didn’t specify what you wanted until now it’s on you as the de facto project manager and designer. Did you plan how it will be anchored into the wall? If you had wanted a solid 2” thick shelf that would have been attached to the wall with hidden steel brackets bolted to the framing. What the contractor planned for is ‘typical’. I doubt he can execute what you are saying (2” thick solid) for the extra $200.

Appreciated

"But original scope says two solid wood floating shelves at 2.5” thick, 12” deep, 42” wide."

If I were a builder reading those instructions, I'd have a talk with the designer, because solid wood of those dimensions would warp terribly if used in the thicknesses of 1/8" up to maybe 3/8" to build the traditional floating shelf box. If you're talking about a solid slab of timber, that's not how floating shelving is made unless maybe you're doing a live-edge application which would require extreme bracing and make the placement of anything heavy on top prohibitive. What is probably going to be done with your instructions is a plywood build with interior spines and openings for the shelf brackets to insert through the back. If you wanted a lip or not on the front, that would be tacked on to the front separately and probably not look very good except from a straight-on view. I got quotes for 2 floating shelves as part of a kitchen build for a total kitchen cabinetry renovation project very similar in dimension to yours, and $200.00 relative to the cost of the actual shelving would be a small percentage if you're talking about a mid-grade, custom manufacturer. All my previous comments apply, that he may be figuring in the cost of a change order as well as the possibility of having to remake the underside of the shelving if you don't like it or if any routing errors are made.