After a marvellous few years at White Hart Lane, the 24-year-old last summer swapped north London for Real Madrid in a record-breaking 100million euros (£85.3million) deal.
The gargantuan fee raised more than a few eyebrows but Bale has not wilted under the pressure brought by the price tag.
The winger has shone in his debut campaign in Spain and so far netted 20 goals, the latest being Wednesday's outstanding solo strike that secured Madrid the Copa del Rey crown at the expense of Barcelona.
The strength, speed and composure shown by Bale in scoring left onwatchers open-mouthed and reinforced Spurs head coach Sherwood's belief that Tottenham should have got more money for him.
"His fee looks cheap now," Sherwood said. "If he is going to deliver them the European Cup - which it looks like he might - then that looks good business [for Madrid].
"To have Cristiano Ronaldo and Bale - he's a freak of nature what you see there.
"When he was running on the track he'd run past three old ladies eating a hamburger and come back on the pitch, and still be fastest to the ball.
"Look at his goal, he was playing against Barcelona, he's had a great season."
Sherwood sent Bale a text message after Madrid's win saying 'Well done mate, keep it going', but laughed as he revealed he did not get one back.
It is no surprise given the number of well-wishers, which included the world's best player present and past, Cristiano Ronaldo and Zinedine Zidane, at the end of a game that left those connected with Spurs wondering what could have been.
This season has been a tumultuous one at White Hart Lane and Champions League qualification is now almost certainly beyond them.
"Give me Gareth Bale and I think we might have been realistic challengers for the top four this season," Sherwood said.
"You saw what Gareth did - eight winning goals last season out of 21 goals and nine assists. If you put them on to our season it would have a different complexion.
"Speculation was rife at the time - nearly as long as the speculation surrounding me.
"He certainly dealt with it and I think to be fair, he wanted to go. Once a player wants to go, it is very difficult to keep him. Unless you are Liverpool of course."