How much money you paid in reality for your steam library.

At least $5.

39.99$

hard to say. i guess at least 5000$. probably quite a bit more. ^^

I don't think I have spent more than $150, which seems pretty good since I have just over 500 games now (and I have a dozen games I have not activated yet because I don't know)

Not a lot. I am also not very good at the maths. So it may be a lot.
Probably not as much as I have paid for my console game collection though.

Steam extension thing tells you how much you spent on steam (obviously doesn't include other websites like HB or GMG).

I have no idea

Maybe $225

Until this past couple months, under 20$, about 60$ now, lol.

No idea. probably $500 by now at least

0$ all hail trading oh I mean gaben ^^

Under 200€... Maybe under 150 :) 667 games

15€

I have 135 games, and spent like 150 euro (only football manager 2014 paid it full....50 euro) others were in bundles or sales :D

Not much, I bought only 1 game at full price (Europa Universalis IV), a large amount were bought with a heavy discount and dozens were gifts either from giveaway sites or friends.

Hmm I don't know, I have 400+ games. I'd say around $250

Somewhere at $200, though value of acc with sales is 725.

Exactly 140 Euros for my 129 games.

About 150$ maybe more or less.

305,40€

Around two thousands maybe.

about $100-$150

edit: $200-220 for past month. That's actually when I started building the library.. I guess no summer sale for me..
And the most expensive purchases were Valve complete pack for $21, Shadow of Mordor for $20, GTA "complete" $9,99...
You don't even notice how much you spend with all this small 2-3 dollar bundles...