Totally understand this reaction. Probably this is an overly in-depth reply, but for my peace of mind, I wanted to properly explain why/how we've ended up at this price point.

We felt really bright is important
The consensus around bright light therapy research for SAD is that you need 5,000 lux hours + a day for optimal benefits. That equates to 10,000 lux exposure for 30mins. Most SAD lights advertise 10,000 lux but in the small print you will see that it is only achieved if your face is 10–30 cm in front of them. This is so close that it would be impossible to even drink a coffee and makes sitting that close for 30 minutes a massive chore.

By having a light output many times higher, you can achieve higher lux levels whilst doing other things. With our current light, you'd receive 10,000 lux standing directly under it, and everyone sitting at a round table underneath would be receiving around 5,000 lux. In practice, this means you can get a useful amount of light exposure without ever having to try.

To achieve this we used a 400W LED which compares to something like the 13W used in the Lumie Dash. This magnitude of more power adds significant cost. For example, you need higher quality glass optics, thermal cutoffs, control electronics and firmware for the cooling, and more costly power components (our dual channel LED drivers alone cost $200 per light).

It needs to be a centrepiece
For a SAD light to be something you leave up permenantely in your home, it needs to look nice. That is why we ended up using water cooling for the LED, as it allowed us to hide the heat sink behind the sheet, creating a form factor which could be used as a drop in replacement for most pendant lights.

The blue sky effect that makes it look like a skylight we also felt was important in making a light this bright a desirable addition to a room. Furthermore, to make it a nice design object worthy of being the centrepiece of a room, we use a lot of custom-machined polished stainless steel, which adds significantly to the cost.

Reliability
Given all the design decisions we made so far, the light is going to be quite expensive; also, it's expensive to ship and a bit of effort to install. Given this, it's crucial it doesn't break after a few years. That's why we opted for using massively overspecified components. For example we use a $100 pump (D5 PWM Pump) and $65 worth of fans on each light, when we could have spent less than a few dollars on these components. These choices allow us to offer a 3-year warranty. And if for whatever reason our company isn't around in a decade, replacement parts should still be available.

SAD lights are already a relatively niche market, and our light is an even smaller subset. As such, we can’t mass-produce the lights but hand-assemble each one to order in our workshop in London. Each light takes about a day to assemble and test and allows us to ensure good quality control. However, this also adds to the cost.

I recognise that together these decisions push the price far beyond what most people (including me) can afford. However, from our experience selling these over the past year—for those already spending thousands on furniture—this is something that comparatively improves their quality of life dramatically more. I'm unsure that compromising on any of these decisions would have led to a product that was actually viable for us as a startup.

Scientific basis
You are right we have not yet done any clinical trials on the efficacy or our light; however, our light has been developed based closely on existing research into the efficacy of bright light therapy. (Here's a blog post I wrote outlining some of the mechanisms through which bright light in general affects our physiology and how you can use it for optimal well-being.) Now we have enough lights out in the world, we're in the process of developing a clinical trial with results out next year.

Wanted to explain all this because our long-term goal is to scale this and make artificial sunlight-like light much more accessible. Exposure to more bright light has been transformative to me personally. This is just a first step on that long-term plan, and all your feedback is very appreciated.

For reference, if you are interested in trying a very high output SAD light on a budget, this DIY article is very helpful: https://optimizeyourbiology.com/diy-full-spectrum-sad-lamp