These Premium Themes display an impeccable aesthetic, attention to detail, and occasionally a specialization (galleries, long text, band sites, business sites, etc.).
They cost between $9 and $49 (most of which goes right into the pockets of the brilliant designers behind them) and are a shining addition to the 350+ beautiful free themes already available.
Check out the launch collection on http://www.tumblr.com/themes/premium
Like I said, it’s fundamentally unfair to compare it with the Nexus. It’s like a non-fatal Toytota, next to a Ferrari.