The short answer
Pay for ChatGPT first if you want a broad workhorse. Pay for Perplexity first if research is your bottleneck. Pay for Claude first only if writing quality is the whole reason you are upgrading. Pay for Midjourney first only if visual output quality is central to your work.
When a broad tool should come first
A broad tool should come first when your AI use is spread across writing, planning, summarising, admin, and idea work. That is why ChatGPT stays the default recommendation. It usually earns its subscription faster because it gets used more often.
When a specialist should come first
A specialist should come first only when the bottleneck is obvious and repeated. Research-heavy users can justify Perplexity. Heavy writers can justify Claude. Image-first creators can justify Midjourney. Voice-heavy creators can justify ElevenLabs.
What to avoid
Do not pay because a tool feels exciting for a week. Pay only once current free access is clearly getting in the way of repeated, useful work. The best paid tool is rarely the one with the most features. It is the one that removes the most friction from your actual week.