If you comp the stats closely, the differential works out. The `02 Vidro has 28% more PA, so that extrapolates to 28% more salary or another $1.1 MM. The bump from B to B+ fielding is worth maybe $100,000. Figure that the jump from range of D to B -- six places on a D, D+, C-, C, C+, B- and B system -- is worth about $600,000.
The 2% bump from .371 to .378 OBP is worth another $100,000 or $200,000 and the increase in power implied by the RBI (96 v. 59, which probably means quite a few more extra base hits) is proportionately greatly than the direct extrapolation of 28% more PA. So you can get from $3.93 MM to $6.30 MM on a strict interpretation of the numbers.
Having said that, mattedesa is right. Who wants to pay $6.30 MM for `02 Jose Vidro? I can't think of too many ballparks or lineup configurations in which he is worth more than comparably priced `23 Rogers Hornsby, `11 Eddie Collins, `52 Jackie Robinson and `01 Roberto Alomar, to name just a few.