I think the site is nice - it's clean and directly to the point. No huge hero and no click-throughs to get to the meat of your project. Prices for your posters seem entirely reasonable. Tangent: I don't understand the fascination with one's own commit heatmap (or any other commit heatmap for that matter). Maybe it seems a bit too self-congratulatory? Vain? I don't know quite what it is, but it rubs me the wrong way a…
That said posting it on a wall to say "Hey look what I've done" its a bit much for me. But I would defintely buy a poster for my engineering team, that would fantastic!