Your numbers don't look reasonable to me. My considerations for a V3, in $US:
- 1000KVA transformer is close to $100K
- Only Tesla knows what their equip costs but I would guess over $100K capex
- Power feed would be 5 figures
- Construction costs would be 5 figures
- Cost of Tesla personnel managing, doing design, presentations, travel to city council meetings etc (unknown)
- Permits, fees etc, landscaping, municipal fees etc. are in the nuisance zone but not zero
- Tech setup
- Initial utility fees to turn the lights on
There is capex, salary, professional fees, lots of other things. I see capex being close to your numbers, but that's certainly not the limit of Tesla's costs. A power transformer and Tesla equipment cost would be somewhat proportional to stall count (with some rounding up) but a 6 stall site would likely have similar non-capex setup cost to a 12 stall site.
Operational costs are likely more proportional to stall count (utility costs, stall rental etc.).
I think my numbers are conservative. I saw other people come up with estimates of a quarter million for 6 stalls a year ago (pre-V3).
Cost in $CDN of course higher.