In this context and in idiomatic English "on" and "for" are interchangeable. There is little or no difference. By convention a quotation is often spoken of as "a price on" and when talking about the cost of an item it is "the price of" but there is no rule governing this. It would be quite acceptable to ask

"Would you please quote me the price of that job?"

Then again it is more conventional to ask for "a price on" but talk about "the price of".

In this context and in idiomatic English "on" and "for" are interchangeable. There is little or no difference. By convention a quotation is often spoken of as "a price on" and when talking about the cost of an item it is "the price for" but there is no rule governing this. It would be quite acceptable to ask

"Would you please quote me the price for that job?"

Then again it is more conventional to ask for "a price on" but talk about "the price for".

There is also the perfectly acceptable "the / a price of..." which can be used in either context. "Quote the price of a pump" and "The price of a pump is ..."