While leveling up to 50/between 50 and 60/60 and 70, etc, ilvl doesn't matter as much. As long as your gear is up to date on level, you ilvl will be where it needs to be as well. Ilvl only really matters during endgames.
And if you buy poetics gear whenever you hit those caps, your ilvl will be fine until the next expansion.

So if you do the above, ilvl is only really a concern at current endgame.