I'm thinking of bringing all my skills up to 1k. It would be fun to know what it takes to get SG there as well.
You'll soon learn that all your skills will mean some very expensive to increase skills (counting only the ones that don't require unlock, some unlocks I think only an handfun of people have yet achieved), so if you aren't even able to find out by yourself how long it will take you to raise something as simple as Sweat gathering to 1000, it is my opinion that you haven't yet think too much about it.
Now how long will it take it depends on how fast you gain skills
that being said if you know how fast you are gaining skills you can get an estimate of how long it will take.
For example
1000 points in SG if the skill was extractable would mean a value in skills present in the avatar of 3.42 PED
(aprox. the source is
http://www.entropiawiki.com/SkillCalc.aspx)
let say that you started today with 1 point and after 2 hours you reached 53 points and the next day with 2 hours you reached 110,
assuming that mob under the same conditions continues to give you a linear increase of the skill gains up to 1000 points (which in this sample of values won't be very far from the truth).
it would be expectable to take 98 hours of sweat gathering to reach 1000 points.
Extracting, 53 ESI needed: 0.07 PED
Extracting, 110 ESI needed: 0.14 PED
Extracting, 1000 ESI needed: 3.42 PED
3.42/0.07=48.85
2h*48.85= 97.71h
So it up to you to find out how fast you are gaining skills,
Those values are just for example and not based in any data that I have, but the general principle is what I believe it is true.