(ねだん) Price of one item. (usually used about a big thing – house, car –  moreso than a gumball or a Pocky. In those cases, you’d just say, ‘いくらっすか?’)   $$$TTT
(かち) Value in general. Can be used about money (a valuable necklace.) but unlike 価, 価値 has a more broad, non-money feeling to it:this painting has artistic value, she values honesty highly, I made a value judgment, the value of learning has no price-tag.   PPPTTT
(あたい) Value – but not an actual dollar amount (that’d be 値段(ねだん)), 価 is value as in "The value of the antique goes up with time’ or ‘I’ll estimate the value, using my jeweler’s loupe and tweezers."
() Value in a math or science sense! A numerical value. One unit – an angstrom or a light-year.
(ぶっか) Price of a commodity as a whole (Gas prices are up! Tokyo prices are higher than in the countryside!) If you want to talk about the price of one item specifically, you’d use 値段(ねだん).
(かかく) A very narrow meaning:unit price. Used when talking about business or market conditions. Or if you are a factory manager who is haggling for 10,000 diodes, wholesale. You wouldn’t say to the kid behind the counter at 7-11, ‘What’s the 価格 of this bag of chips, dude?’
(こうりかかく) Retail unit price.
(おろしかかく) Wholesale price.
(ねだん) PRICE - Use this in stores.