In order to have multiple prices 'one on product' you would need to use custom options, so that the customer can select the size option on the product page and the price change based on that selection.
For more details on custom options see the Magento documentation: http://docs.magento.com/m2/ce/user_guide/catalog/settings-advanced-custom-options.html
For an import example based on your data above see below:
Note each custom option is split in the above example using a '|' and each setting for each option by a ','. The settings for each option reflect those provided in the admin area for a product with the '=' separating the setting title/code and the value.
I would also note that whilst this is a perfectly valid way of creating this product, if you need to manage stock for each of these prices options you should consider using a configurable product: http://docs.magento.com/m2/ce/user_guide/catalog/product-create-configurable.html
Finally please note my findings were from testing on Magento CE 2.0.7