Well for garden irrigation - improve idea - please provide input

We need quite a lot of water for our garden. There are a few minor things bothering me about the current situation (use of drinking water for the garden, wastewater fees, also the use of outdoor taps in front of which the descaling system is installed - a mix of poorly thought-out planning and negligent behavior). So, a well is to be installed.
With a height difference from well depth (approx. -30m) to upper garden (+20m), the pump has to be quite a monster. Therefore, my idea is whether I could fill a 5m3 water trough from the well and then use another pump from this trough, which also collects rainwater from the carport, to provide garden irrigation. Conveniently, I could control the well pump for filling the cistern via the photovoltaic system and float contact so that it only operates with self-generated electricity.
The water trough and additional pump are already planned.
Who has experience?
What are the advantages and disadvantages of my considerations?
Are the cost assumptions realistic?
Check where water is and set location – feasibility: 150€
Drill hole including piping: 80€/m at 30m = approx. 2400€
Well pump with hose and tap: 1000€ including installation
5,000l water trough: 2000€ including delivery
Pump in water trough with tap: 700€
All-around work done independently, materials (pipes, hoses) and beautifying: 350€
Total approx. 6600€ (I realize that this is not quickly economical with savings of about 400-500€ p.a. on water and wastewater)
Thanks in advance for ideas, criticism, or encouragement.

Have you checked whether you are allowed to drill a well?
We are not allowed to, for example.
And drill really deep with a buffer. Friends of ours had their well practically dry up during the last hot summers. They then drilled a new one together with the neighbor.

In principle, the idea is good, but you still have to drill 50m or did I misunderstand that now. Furthermore, do you really want to put such a 5sqm barrel in the garden?

Why still a tank and another pump? Just put in a proper well pump and that's it. For example, Grundfos sq 5-70. Whether you use it to supply automatic irrigation or faucets doesn't matter.

We need quite a lot of water for our garden.

Does that mean in liters or m³? 100,000 l or 100 m³?

Have you checked if you are allowed to drill a well?

Yes, my preliminary inquiry with the district was positive.

In principle the idea is good, but you have to drill 50m or did I misunderstand that?

The 30m is an estimate, an additional 20 meters of elevation come on the property to reach everywhere water should go.

Furthermore, do you really want to put such a 5sqm barrel in the garden?

No one will see it at the planned location and it will blend in. I have meanwhile found IBC containers with overflow, costing only around €100 per cubic meter, so you can start with 2 or 3.

Why still a barrel and another pump?

The barrel with pump is anyway for draining the carport. There is 35sqm of roof area on it.

Just put in a proper well pump and done. For example Grundfos sq 5-70.

The idea is to use a pump with lower throughput since it only refills the storage when in use. It needs less power and can therefore be smaller sized, right? For that, an sq 3-40 should actually suffice, right? Honestly, I don’t understand the specifications. In the past, a tip from the hardware store worked in a small hole...