Need theorycrafter input on gear upgrades:

[Alhanelem]

I recently obtained a relic weapon, and I have 900 mythology stones this week.

Which is a statistically better upgrade for summoner (main stat differences listed):

Relic weapon -> Relic weapon +1 (+2 physical +3 magic damage, +3 int)
or
AF body -> relic body (+15 int, +11 crit)

I've been hearing conflicting info as to how much of a primary stat is equivalent to a point of weapon damage, so I'd like some info on this, either a post or a link to someone who's worked this stuff out.