"Good enough", Demand, and Scale.

The contractor grade stuff is designed to be durable and good enough. Most people will find it attractive and suitable for their esthetic. Seasonal re-designs are safe by following design trends established at trade shows. Contractors can rely on the product not failing so they continue to buy it for all their projects.

The fancy stuff is often made for different countries and can have different parts and specifications. If more (assuming we're talking about America here) people wanted this stuff, the manufacturing would increase and the costs would come down. However, a lot of times the reason people buy the expensive stuff is specifically because it's bespoke and "hand crafted". If a Gucci bag cost $50, it wouldn't be worth the name.

You need demand to bring down costs. This increases the scale required and ability to afford better technology to make more.

The tools needed to manufacturer something at large scale are expensive. If you house your own tools, how are you going to buy those tools if you don't have money to buy them? If you're going to contract manufacturing, why would a manufacturer make you something for little money when they can use their facility to make exponentially more widgets for another company? Just swapping out a die on a machine costs money. They're not going to disrupt existing manufacturing for a few hundred widgets.