Rarely does someone who is capable of designing something like this possess the knowledge to make it accurate. It's still the best of its ilk that I've seen.
I reckon these guys print on "80-pound card stock on a digital offset press" because that's what adds value for them. If the shipping wasn't so high I'd buy this because it's nicely executed and pretty to look at in and of itself. I'd also buy an improved version if it was made available after the original.
Regarding the copying/printing without permission: This is how design works in the internet age. As a producer, good design buys you reputation but not much more. Quality real life production of that design buys you the retail worth of that production.
Copying that design for sale costs your reputation unless you are adding some serious value.
alkos, cost to your reputation is practically zero because you are not trying to sell this, you're just trying to avoid buying it. If you were printing it off in batches and selling them to your mates then the cost to your "internet" reputation would be high outside of the group you were selling to. If you were carving it into wood and selling the result the cost to your reputation would probably be outweighed by the added value of your craftsmanship (assuming you're a good carver).
It's weird how value is allocated on the internet. You'll see a lot of art/design products that take their value from limited production numbers or high quality production methods. But at the same time the design is available for anyone to reproduce in lower (or even higher) quality. Why this doesn't translate to T-shirts is beyond me.
This is the longest post I've ever made. Possibly due to tesco's current deal on Hobgoblin.