If it's a custom made lens, the tooling for the lens production. If it's a custom housing the tooling for the housing production too.
And enough profit built in so that a retailer will make enough from your product to want to sell it. Without that there will be no bike shop sales, or big mail order company sales etc. And labor to assemble the product depending on where they are made.

Those are probably the highest things. The custom made circuit board would be another if that light has one. But the fixed costs like mortage or rent and utilities can vary so much it's hard to guess about one particular light. The cost of living from country to country and even from town to town can really change things.