Yes, of course.
Knuffel only version. LEVEL 20:
Profit: 4000
Readoption price: 1900.
Benefit: 2100
Benefit per XP: 1,058
Knuffel + cupcake version. LEVEL 30:
Profit: 6000
Readoption price: 1900.
Cupcake price: 1700
Benefit: 2400
Benefit per XP: 0,536
Knuffel + cupcake + apple version. LEVEL 60:
Profit: 12000
Readoption price: 1900.
Cupcake price: 1700
Apple price: 1400
Benefit: 7000
Benefit per XP: 0,389
In my opinion, the best choice is not the one which brings a better benefit (which is, obviously, level 100) but higher benefit per XP.
I usually don't buy neither cupcake nor apple, but I stick to giving them up between level 20 and 30.
I can show you my spreadsheet if you want.