I've bought the things Saggitarius want to get. They are in my inventory. But when I click 'Finish' he only says

Oh No!

I expect a certain amount of sP to be put into my quests. Sadly, you just can't provide that.

Back to last page shows me the same requested things before and when I click 'Quit' I get the same message.

Is this already known? What this message mean?

- You can only complete Saggitarius' quests if you have more than a certain amount of sP on your account. (Google tells me it's 700k+).

You probably dropped below this amount when you bought the items for his quest, so now he won't let you turn them in until you earn some more sP to get back up past 700k. :(

If you do some other quests or play a few games really quickly, you may be able to get your sP back up before your Saggitarius quest ends and you get stuck with the items you bought for him.

Thank you very much, I collected some sp and Saggi took my items. Good to know this information.

Locking as this is not a bug!