We needed the unique jobs feature, which only part of the enterprise plan.
And since (at that stage) our budget was low, the enterprise plan was too expensive.
I reached out to ask if we can do any other payment scheme, or at least get startup discount to start using, but were declined.
We ended up using an OSS library for that part and even now what we grown, still don't pay for sidekiq. If it was part of Pro, or we had a 1 year discount for startups, we prob just kept on paying even now (that we can afford it).