I know this is a simple design, but it's just that, the simplicity of that design, that's the beauty of the thing. I won these for about $180 on eBay, and while I might be able to build a comparably priced pair, it wouldn't be worth it to me.
Similarly, I'm very content with the Trends amp as is, which I also won on eBay for about $100.
This is a real fun little set-up that I really don't have home for right now, but it isn't going anywhere soon, I like it too much, so it'll be back into the closet until I can find a place of it in the future.