I used group buys for almost an entire year, and they are super unreliable and people change the passwords constantly. But when they work, they are well worth the money and they provide access to more than one tool which is a plus. But to be completely transparent, I have been using the standard plan ($1,790/yr) of ahrefs for the last 9 months and I'm never looking back. I use it every single day, and out of all the SEO tools I've used it's by far the most comprehensive and accurate. Additionally, they have an ahrefs insider FB group for members, which is an incredible community. They also offer tons of valuable resources and constant updates to their tools. I know it's a difficult investment to justify, but it absolutely changed the game for me. Not only have I been able to streamline all my work into a single SEO tool, as I previously mentioned, it's hands down the most comprehensive and accurate of all the major tools and the quality of my client work has absolutely skyrocketed because of it. I seriously can't speak more highly of ahrefs, the tools, and the team. It's paid for itself ten-fold in the 9 months I've been using it, but I would have a much more difficult time justifying this purchase if I wasn't doing client work, or my solo projects didn't already have a steady stream of income.