How much do you want to spend is "¿Cuanto quiere/quieres gastar?"
Quiere is used if you are speaking formally (to someone older or of higher position than you) and Quieres is used if you are speaking informally (to friends, siblings, etc.)
gasta mucho
i want to see you tonight and spend time with you before i leave
gastar
Cuanto quieres pagar?
cuanto azucar quieres
To say 'I want bread' in Spanish, you would say 'Yo quiero pan.'
as much as you want but she your sister i would say 20 but you pick
To say 'I want meat' in Spanish, you would say 'Yo quiero carne.'
To say 'I want cereal' in Spanish, you would say 'Yo quiero cereales.'
To say 'I want paper' in Spanish, you would say 'Yo quiero papel.'
To say 'I want a chair' in Spanish, you would say 'Quiero una silla.'
To say 'I want to eat a carrot' in Spanish, you would say 'Yo quiero comer una zanahoria.'