Well, if the Dodgers had a cheaper version of Mookie Betts, why would they trade him for a more expensive and older version of Mookie Betts?
The equal value is, as others have stated, one year of Mookie Betts vs 5 years of Alex Verdugo, plus lottery tickets of Wong and Downs. Dodgers were nice enough to take 1/2 of Price's contract in the deal too.
Mookie Betts 2020: 2.9 fWAR
Verdugo since 2020: 3.8 fWAR