Hi,

In product_template model, there are five price-related columns: 
price, list_price, lst_price, standard_price, pricelist_id.

In product_product model, there are three price-related columns: 
price, price_extra, lst_price,

standard_price: This is the cost or purchase price of a product. It is used to calculate the cost of goods -- mostly for accounting purpose.  Whenever its value changes, Odoo calls _set_standard_price to store value history in the product.price.history table.

price_extra: The price_extra is a computed field. A product template may have multiple product variants that have a combination of some attribute values. An attribute value can have an extra price. For example, 32GB memory may add an extra $50. The sum of hose extra prices for applicable product variant attributes will the the price_extra.

list_price: This field is the sales or product price displayed in a web site. When one wants to change the list_price of a product, it should change it in the product template. For individual product variant, change the attribute extra price.

lst_price in product_template model: it seems that the lst_price field can be used for both product_template and product_product as the product sale price. In product_template model, it points to the list_price field.

lst_price in product_product model: In product_product model, it is computed field that calls _product_lst_price. 
This function calculates the lst_price of a product variant by adding its list_price and its price_extra. 
The field also has an inverse function _set_product_lst_price that sets list_price when lst_price changes. 
The list_price value is the subtraction of price_extra from lst_price.

For a product variant, the lst_price is the sales or product price displayed in a web site.

price In both product_template model and product_product model, it is a computed field to calculate its value.
The method uses product.pricelist model to calculate a price based on rules defined in product.pricelist.item. 
any context variables, such as partner, UOM, currency and rule name, are used in finding the price. 
The price_get method is called in the calculation.