The Bosch ones do seem to be a good price. It's not necessary to match the number exactly; staying within a reasonable band is OK.
Your Varta spec shows up the different ways of quoting CCA. Your 380A is DIN spec which is equal to 640A in the SAE spec, which is the one used in many adverts simply because it's a larger numebr and "looks better" .
You'll need to check that my examples are correct for your car.
Varta battery sale price, scroll down: https://advancedbatt...tab-description