looking forward to moving away from YNAB. it became too expensive for what it offers (note: i can't use auto-sync) . On the other side, i've 3+ years of data and various script to overcome problems such us import from csv, auto-split categories etc. Thus, if someone find an easy-to-use alternative that has budget and bookkeeping that would be great.

My favorite YNAB alternative is Buckets - https://www.budgetwithbuckets.com/ although especially if you don’t need auto-sync

Is there an open source alternative to YNAB that operates under the same budgeting principles?

I'm a YNAB guy too, and I look for a cheaper solution every year when I have to renew it. Last time the only real competitor is Monarch Money and they don't support anything other than usd.

I used it about a year but switched back to YNAB. I really like the budget in YNAB. Firefly concentrates more on the bookkeeping. Which for me is just secondary...

It's kind of mind blowing that there isn't a lot of cheaper alternatives to YNAB that focus on budgeting.. YNAB is so popular (and so expensive)