The 26-year-old, who was linked with a move to West Ham earlier in the window - as reported by the Evening Standard - has signed a five-year deal with the club having rejected a new deal at Turf Moor.
It represents good business for the Clarets who have doubled their money on a player they signed for £9m from Brentford back in 2015.
But the sum has understandably raised eyebrows among fans and pundits.
In fact many have suggested the figure is more alarming than the world record £200m PSG have shelled out to sign Neymar.
And not signing the former Luton Town forward could be the best transfer decision Slaven Bilic makes this summer.
Aside from the controversy which followed Gray around last season following his four-game ban over historic homophobic tweets, it is his performances on the pitch which offer no indication as to why he has attracted such a large bid.
Gray scored nine goals last season, his first in the top flight.
But the most alarming stat of all is the fact he played in 32 games and failed to score in 26 of them.
His nine goals were spread across just six games and three of them came in one match against relegation fodder Sunderland.
Gray was only being looked at as a back-up striker for the East Londoners and perhaps there is a case to say he may have offered pace from the bench.
But at nearly £3m more expensive than proven world class striker Javier Hernandez - Mexico's all-time leading goalscorer with a ratio of a goal every 1.4 league starts - the numbers just do not add up.
Bilic, and most Hammers fans, will consider Gray a bullet dodged.