I lived and died by v1 rental throughout my whole Splinterlands time so yes, it's worth it. They say v2 rental is even cheaper now so the ROI is higher by default.

On the other hand, I have struggled to breakeven with the lowered tournament prize nowadays at the lower end so I think the right strategy is to just rent core cards that are super useful in general. My method was renting everything to a decent level, so it's a higher rental output than one should need to pay.