Perplexity, the AI search engine startup, is a hot property at the moment. TechCrunch has learned that the company is currently raising at least $250 million more at a valuation of between $2.5 billion and $3 billion. The news comes on the heels of two other big fundraises that have seen company’s valuation leapfrog in the last four months: in January the company raised nearly $74 million at a valuation of $540 million (up from $121 million in April 2023). And at the beginning of March, the comp...