Why are these so special? I know it says 'This is the weekend special quest! That means increased prizes!' but i haven't ever seen anything increased. I am doing Quentin's now but his prizes are are the same as usual.....crappy! This seems to me on all weekend quests, I have never gotten anything more than what you get anyway.

Do we have to do something special/spend more?

Afaik Quentin has a chance to give out special items during their weekend quests, other than that I'm not sure either what's so special - but that not only applies to these quests.

Yeah, I recall weekend quests used to give increased rewards, but the weekend quest rewards have been pretty underwhelming lately.