So I finally reached 50 Questpoints and now I can't decide about how I can spend them the most profitable way. I don't really need any of the items offered, so I'd like to resell the item as soon as possible. Do you guys have any clever tips on this? I bought some Mascara at the subeautique once but now I can't really get it sold, thats what I'd like to prevent. Also, do any of you want anything (rather expensive) from the Questshop? As I'd like to sell the item as soon as possible I'm willing to offer a rather low price.
Quest shop items and subeautique makeup which always stays stocked are kinda tough to sell considering a lot of players have tons of quest points and can buy it any point themselves for free. Like as for me I have 500 lingering around I still havent spent bc I dont need anything xD
But I suppose if you want to give it a shot the books, stickers and nice wearables MIGHT sell. Could take awhile though, bc like I said, lots of people have tons of quest points.

Personally, I would just advertise the 50 points for sale in the Advertising forum. List your rate of sP per point and let people tell you what they need, and just buy that. They'll probably sell a little bit faster than choosing an item yourself and hoping someone needs it
You might try buying the special seasonal stuff in there. Right now, there are a bunch of autumn themed items. Those will be removed at the start of winter and won't be available until next autumn. They are usually at the bottom of the stock and tend to be a bit pricier than those items that are in the shop all year. I remember forgetting to buy some special birthday items last year and their user shop price were pretty high after they got removed.