In case it helps anyone, here are our material costs for outdoor facilities from 2020 and 2021. Everything 100% done by ourselves.
Terrace: 50 sqm
Paving stones: 100 sqm
Curb stones: 50 m granite
+Curb stones: 60 m concrete
Fence: 90 m double rod mat
Gravel: 120t - 3300€
Chippings: 13t - 300€
Concrete: 15t - 800€
Granite terrace slabs 80x80 50 sqm + granite curb stones 50m - 4000€
Paving stones 100 sqm - 2200€
Tools (buy or rent) - 500€
Concrete curb stones 60 m - 500€
Fence double rod mat 8/6/8 90m between 100 and 140 cm - 3000€
Fence granite posts: 1200€
Well + automatic irrigation - approx. 1000€
Robotic lawn mower - 800€
Truck with sieved soil - 600€
Lawn + miscellaneous small items: 500€
Total sum approx. 19,000€ all 100% done by ourselves.
Still missing completely are all plants + terrace roof.
We got a quote for a 50 sqm terrace roof: 26,000€
To do this 100% ourselves as we want, about 15,000€ material only.
=> Outdoor facilities, when finished, cost us 34,000€ material + plants.
These were hundreds of hours with father and father-in-law.
Therefore, I am by no means surprised by estimates in this forum for garden and landscaping contractors of 70,000€.