This is a pretty great price for one of the best franchises in PC gaming. Yes, there is no DLC included (as far as I know) but even without that the games are extremely enjoyable and you will get a lot of playing hours out of the trilogy (even without DLC).
Not sure how long this lasts. Also not sure if it is one key but I guess it is.
Note: From Origin directly it is $7.49AUD hence buy from there if you want it:
I cannot change the link over.