chepest way to sustain an Alfa sim card?

Honestly, there is a plan to renew your phone line for 30 days for about 100k (waffer)--that's probably the cheapest I have seen for bare-bones. I think you can get the 500mb plan for 30 days for $3.50 (80ish thousand) which I would recommend over the other plan as at least you would have the option to call people on whatsapp instead of using actual credits to make an actual phone call.

https://www.alfa.com.lb/en/mobile-broadband/about

https://www.alfa.com.lb/en/prepaid/plans/alfa-waffer-4.5 (waffer khat).

They do have a plan simulator--maybe check that out see if you get other options. Since they are on strike, I doubt you will be able to get a person on the line to help you out.

Not sure if you can port your number to it, but there's a plan called Alfa 365 where the line stays valid for a year for 5$: https://www.alfa.com.lb/en/prepaid/plans/alfa365