Anniversary set? Singles or packs?

With the imminent arrival of the Anniversary set, I'm thinking about dipping my toe back into my first set since 151.

I can see retail prices for ETBs aren't terrible but I imagine they'll be more rare than fairy dust. Are singles still the best way to go about this one do we think? I have a complete set of 151 done purely off eBay singles - no packs opened at all for me.

Or might it be worth an ETB to hopefully snag one of the big hitters?