I would've preferred to flat call the big blind then call any raise which would've hopefully cost much less than the £3075. Say it had only cost £2000 to call then the implied odds are about 12 to 1 and much more favorable.
but in this spot we dont know we have the implied odds of his whole stack as we cant defo have him on AA/KK/QQ from just a raise over a caller. much different to a small 3bet over and ep open.
We never know for sure though. That's why they're implied.
I guess I'm a bit of a stack protector and wouldn't want to put in quite so much on a pair of sevens. I prefer to put in 10% of my stack for a 50% chance of achieving my implied odds than 20% of my stack with a 75% chance.
(Made up figures, they came from nowhere so no need to tell me they're wrong)