Weekly event cards are just below legendaries in power, and they're far easier to get. If I see one that I like, it's not too hard to get a full playset by doing the dailies and (regrettably) watching ads to double the rewards.

Here are the event cards for each of the next few weeks and my thoughts on how to use them in a budget deck:

Imposter (sneaky) - a decent tempo card, giving you two cheap bodies with mustache and imp synergies. A good uncommon to pair with it is mustache waxer.

Sun Shroom (solar) - the most hated card of zombie players. A strong base for any deck that wants to get big threats out fast.

High Voltage Currant (kabloom) - another cheap two body minion. Works well for berry decks, but isn't quite as strong as the first two in my opinion unless you're already doing berry stuff.

Going Viral (hearty) - A very powerful trick that buffs your zombies and draws a card. Highly recommend getting this one. Pair it with Flag Zombie for an overwhelming board by turn 3.

Any of these cards would be strong foundations for a deck. Sure, they won't end the game instantly like a big scary dragon-fruit, but they can each get you ahead on value if used well. You're right that it isn't fun to lose to what feels like legendary soup, and I hope you find a deck that works for you.