Huge fan of the non-seat/monthly based pricing. Do you need it to be higher to not just cover costs but also make a profit?
At the moment I currently have around $600 of revenue on $1200 spend, but that's primarily because I'm subsidizing new accounts (each new account gets $5 to spend for free, which translates to around ~36 designs). I'm in the process of doing an angel round, so I can afford to operate at a bit of a loss during the growth stage.