Got my Model 3 LR RWD June 5th, 2018. Really wanted EAP but at $6,600 was just to much at once, so I assumed that I'll get it later for $7,900 afterwards (that's EAP). The FSD at the time was $4,000 before delivery and $5,300 after so it'll cost me $13,200 to upgrade afterwards.
Fast forward to before March 5th and the price was $5,300 for only AP (Autosteer & TACC, SINGLE LANE only). FSD now has all the "self driving" features to the tune of $9,200. This totals $14,500 for after delivery so no go. However, saw the Tesla blog post that it'll be offered for half so I waited nervously. I was surprised that both AP & FSD were offered for $6,600; so I pulled the trigger. Now waiting for my car to update (3 days).
If you take into account the price drop from $64,100 to $58,400 ($5,700 difference) and add $6,600 upgrade, that equals $12,300. That's $2,200 cheaper than if you buy a M3 LR RWD now and upgrade AP/FSD later. It's a good deal.