Rental is decent again, so I kinda stopped playing. You can consider Rentvesting. It's based on a home-owning strategy whereby you rent where you want to stay and own an investment property within your budget.

After playing a while, you know what kind of strategies you like to play, so you rent out everything you aren't keen on and rent those that you like. This way you can rent higher level cards and not feel the impact to your DEC balance. Maybe the rewards from playing in the higher league can offset a little of the difference :)