You can get an Ableton Live Lite license for ~$4 by buying certain phone apps.

Eg, the Koala Sampler app comes with a license for it, and it's actually a very fun wee program in itself.

It's not full Ableton - but it's incredible value for $4.

Depends how much of Ableton you're using, Ardour may be usable for you. But it's definitely limited if you want the more professional features.