I can't be alone in thinking that these prices are insanely low when considering the market. If you're selling to working programmers, $9.99 a month is a frivolity. I pay more than that for Netflix. For a business expense? Your $24.99 plan should be the entry point.
You should have a higher tier. A much higher tier, in fact, like $350. You're targeting agencies and studios at this point. It's still under the ~$500 that requires approval, but there are absolutely businesses out there that will just sign up for the highest tier they can process, because it's a status thing or "they may need it". You won't get many signups at this price, but even one will replace 35 signups at your current lowest tier. Heck, more, because higher-priced customers will churn less and require less support.
Consider dropping your free tier and just relying on your free trial. You're targeting businesses and working programmers. They have money, so a lack of money won't be the reason they choose not to use your product, only product/customer fit.