It probably doesn't make that much difference when you buy except for possible tax consequences and if you are in an IRA there are no tax consequencs. You can buy now and set it up immediately as a DRIP. When it DRIPS and you end with new shares the price per share will also probably drop about the amount of the dividend.
Or you can wait to buy after the divy at a lower rate and get a few more shares then instead of through the DRIP. In either case, you will probably end up with approximately the same value. There will be deferred tax consequences by waiting to buy after the divy vs. tax consequences this year by buying and collecting the divy this year.
Of course that all depends on nothing erratic happening with the share price during this short time period.