Landscaping is £££.
During lockdown, we had our garden done as it was effectively a jungle that couldn't be used.
4 skips (£1,200) plus 6 man days (£1,200) down, and we were ready to start.
We had:
10 brand new 6ft fence panels either side, plus 3 across the back (£2,800) plus fitting 4 man days (£800)
Indian sandstone patio of 10m2 including fitting (£2,000)
New lawn of 100m2 laid and bordered including fitting (£2,000)
Total cost = £10,000
While it looked gorgeous, this was a very very basic garden, on London/Surrey borders. I'm not surprised your neighbours was £36k, given they had the full works.
First picture is afterwards, second picture is about halfway through clearance, and a big tree had already been razed. It was a complete mess.