Going big on coal recycling plants!

So I'm in the 1 day process of upgrading my coal recycling plant to level 4, and I stopped to do some math on how much the upgrade to level 5 is going to cost me. Almost have the 800 ewp and 1000 granite saved up, but that isn't the only cost related with this upgrade. It takes 7 full days for this upgrade to complete and there will be no coal production during that time. So besides the planks and granite it will end up costing me 11,858 coal during that time, which seemed like a ton when I thought about it. However If I use A few friends baskets on this every day I'll end up with a building that produces 3705 coal in a 24 hour period. That's equal to 1.47 times how much a level 2 coal mine would produce if similarly buffed. So That coal mine at level 2 is going to run out in 2 days of production, at a cost of 100 hw, 100 marble, and 225 tools per day of operation. I think it ends up being worth it in the end, anyone else upgraded their's to level 4-5 yet, or other thoughts on the top tier upgrades?

When ur friends buff 24 hrs ur recycler, u'll get 3705 coals ahh right. But if u first upgrade it to lvl 5, then buff 24 hrs, u'll get extra 2 coals every 3 mins, 40 an hr, 960 a day. By the time u upgrade, u said u'll lose 11,858 coals OMG! alas u can get those back in 12 days. Later all the coals r yours.
So I would suggest to get some cokers and mines when your recycler is upgrading so that u won't lose that 11k coals. I think it is worth upgrading recyclers though I haven't yet cuz I don't have granites and ewp :o