Is it worth targeting card drops?

[universal123]

What I mean is, is it worth it to stick to earlier levels for faster kills and therefore better chance of getting more cards, or at the moment is it best to keep earning more gold to get more upgrades by farming the higher levels? I mean at the moment progression is fairly slow either way, but just wondering if anyone has done any calculations on this they'd like to share.

[WhiteK]

it depend on you , for example like me i can do 226 but instead i try to finish the 50 card at 176 then move to 201 then 226 , i not very focus on lving stuff i more like have bigger damage :3