Anyway, my friends and I were very reasonable and didn't spend too much money. I got small set to make myself a necklace and two pieces of jersey fabric to make hats for my two little ones.
Then it took me some time to find a pattern, and finally two weeks ago I managed to get round to sewing both beanies:
I found the pattern from the blog "Hamburger Liebe" (there). It is in German, but really not complicated to make. It took me about 1h30 per hat in total and I am very satisfied with the result. Another plus on this pattern is the number of sizes available! You can perfectly make your own adult hat from the same pattern. So I am definitely keeping it for future projects and recommending it!