How to reduce the fee link to a weekly purchase of 5k Sats?

Peace
I am buying SATs weekly with the resource I can spare in this crazy time. I don't know if the fee link to my transactions will damage my plant to save as many as possible offline in my bitcoin wallet. Is it the best option to go weekly or monthly?
Considering my low income, I am looking for another way to make it work.

https://stacker.news/items/1462740