If u have 0/4 pieces then do like this !
Collect 400 cookies and buy the piece nr 3
and then try to collect the other things
becouse if u take the other things first
the nr 3 will cost 1600 cookies
i got the 2nd piece from chest, then bought the 3rd piece (gift holding) one for 400 gingerbread, now part 1 and 4 are 800 gingerbread men, but if i buy 1st part for 800 the 4th will change to 1200