Depending on the plan and amount of work. Bridgeflare stops your containers after idling for 10 minutes then boots them up again once needed (to avoid burning money), so if you're already on the 5$ plan and doing normal workloads, it should fit in the plan.

If you're running them live 24/7, then costs can be in 40-70 dollar range, depending on the workload done/type of instances.

All of my usage last few months has been in the 5$ plan, as they go idle as soon as I stop testing and come back up when I need to test.