The Red Devils were keen on signing the prolific Uruguayan forward last month following positive talks held between agent Walter Guglielmone and the club's power-brokers.
United, though, decided to walk away from the table after crunching the numbers on the former Napoli star, with fears they were also being played off against Atletico Madrid.
It's understood PSG were demanding a transfer fee of £25 million despite the 32-year-old being out of contract this summer, something bosses in Manchester could not entertain.
Cavani was also asking for wages of £250 000-per-week, which meant over the course of a requested three-year deal United would have been committed to £61 million before agent fees and a hefty signing-on bonus were also factored in.