'Of' is probably the most used preposition here, but preference is context-dependent. 'A price on' connotes 'a price set/levied on' (probably not the actual words) and is more seller-orientated. 'The price for' is nuanced less towards the involvement of the seller, and more towards the product (or even buyer). The price for it / for me to get it.
"price on" and "price for" - English Language & Usage Stack Exchange
The preposition "OF" is used here to indicate that the price belongs to/is used in relation with prices of spare parts. Now, the definition of "FOR" as a preposition- For Used to indicate the use of something: Some examples of "for" as a preposition- This place is for exhibitions and shows. I baked a cake for your birthday.
"Prices of" vs "prices for" - English Language & Usage Stack Exchange
The wikipedia article on pricing covers several of the factors involved in pricing strategies and setting. Alternately, "pricing" can be a verb meaning to apply or determine a price", as in "I'm using the label gun to price these cans of tomatoes", or maybe "I'm pricing the items for the garage sale" (where "pricing" means "to decide on a price").
Your best form is "How much is it?" if you want a natural sound. For "What is the price," it is better to ask "What is the price of ABC" or just "What is the price?" Asking "What job are you?" is making me equal to a job, and you want to know which one. Well, I am American, but I do a job. I am not my job.