“The issue when your only tool is a hammer is that you see everything like a nail” - Same thing applies to SP resellers.
Is (850-420)x 122=55bn correct? Almost, you’ll need to subtract tax but let’s say its fine.
The calculation leaves a few things out: The character’s SKINS, implants, LP, standings but for the sake of argument let’s say the character has none of those.
It also conveniently ignores the value of the skill books themselves.
1,280,000 SP in Advanced Drone Avionics costs 0.6m isk for the skill book.
1,280,000 SP in Advanced Information Psychology costs 36m isk for the skill book.
1,280,000 SP in Advanced Spaceship Command costs 50m isk for the skill book.
So yeah, if the only thing you care for is SP as the raw materials for skill injectors you can ignore the value of the skill books.
But what if you actually wanted what this 66m SP character has to offer?
Well, you can train one just like it and assuming you have +5 implants all the way, about 2m SP/mo, it’ll take 33 months. Assuming instant gratification has no value, it’ll cost you 3600 PLEX x 2 for the first two years and 3,300 for the next 9 months for a total of 10,500 PLEX @ 5m/per so 52.5bn isk
What if you really wanted this 66m SP right now? Well you could inject them: The first 5m SP will set you back 8.5bn isk (need 10 injectors at say 850m per). The next 45m SP will set you back another 96bn (need 113 injectors/400k SP each for 850m per). The last 16m SP will need 53 injectors/300k SP each for 850m per, which will cost 45bn. So the total cost will be 149bn isk. So instant gratification costs about 100bn isk, interesting…
To sum up: the seller can ask for anything from 55bn to 150bn, depending on who the target audience is.