Housing - 4000 to 6000 SEK for a 35 - 50 mm2 apartment.
Food and drinks - 1500 to 3000 per person. Truly depends on where you shop. I buy mostly at Frukthalle or in Kviberg.
Internet - 299 to 499 per month
Cellphone - 199 to 599 per month. Cheaper prepaid are also available.
Commuting - Monthly ticket at Vastraffik is around 610 SEK.
Total it could range from 7600 - 10700 per month.