Okay, so I looked it over.
I'm missing 48 classic cards. Most of these are epics and legendaries. I think my biggest gap is that I'm missing two crucial warrior cards, Brawl and Shield Slam.
24 of those 48 are legendaries. I'm missing every class legendary except Tirion Fordring. The only neutral legendaries I have are Lorewalker Cho, Leeroy, Sylvanas, Ysera, Deathwing, and Malygos.
Based on that information, do you guys think there's much value in my throwing gold for another 20 classic packs, especially since Millhouse Mana-ass just reset my pity counter, or am I good to go since the odds of getting legendaries is pretty low and that's largely what I'm missing?
EDIT: And if I don't get more classic packs, should I save these for the new one or is it worthwhile to buy Old Gods packs? I've only bought three of those in the past, mainly to get certain Warlock common cards I was lucky enough to actually get.