Starting from 6th April 2021, Google will begin reviewing the price match between the data feed, website, and checkout. Before this policy, Google will only be checking if the prices matched between the data feed and website landing page (visually and structured data).
Make sure that the prices are always accurate!
You will have 28 days the time to resolve these mismatches. Otherwise, your account may get suspended. Repeated violations may also contribute towards a suspension. It is recommended to check your Google Merchant Center weekly to avoid issues. Price mismatch can preemptively get resolved before Google flags you for a violation.
However, generally, Google does not like frequent price changes, as it takes a while before the ads get updated. Due to this time lag, frequent price changes means your prices are never accurate. This will then lead to a suspension.
Avoid changing the prices frequently and keep the time you change the prices the same. You can then set up the data feed schedule just after changing prices. If you are using daily schedules. This reduces the risk of price mismatch.
That is a good question, while it is rare to see price mismatch. The most common cause is ip based changes. This is not allowed. Or merging the shipping price with the product price.