depending how many total stats you have, crit is generally considered between 2-4 stats.
seeing we don't know how +critical strike affects your chance to crit, we can't give exact numbers. Although i would argue the more stats you have, the more value crit has over more stats.
Some research was done here:
https://forums.d2jsp.org/topic.php?t=80541143&f=74From my own testing with clubs with crit, it seemed to me that +7 crit added between 5-10% chance to crit. I would suggest that +1 crit adds +1% chance to crit a a rough estimate, Not enough testing has been done on this, although comments from the topic i linked suggested similar.
Just as some inaccurate guidelines:
Club/Dagger crit chance: 2%
sword/staff crit chance: 5%
Axe crit chance: 10%
Caster charm crit chance: 20-25%
There's general agreement on axes being higher than the other weapons, however lots of people have lots of opinions on the other 4 weapons as some people suggest daggers chance to crit is much higher.