"Mismatch price" is a very common Merchant Center error. Here are the steps to fix it.
If you have a lot of "mismatched price" errors, there is a high chance of your account getting suspended. To avoid this, you need to have a look at the schema of your website. Google uses the schema to identify the price and offers of particular products. If your schema contains more than one price or offers, then your products can get disapproved.
To fix this issue, use the Google Schema Checker, and validate the product data. You can follow the steps below to check the schema.
Step 1: Open the Google schema checker: https://search.google.com/structured-data/testing-tool/u/0/ and the enter the URL you want to check.
Step 2: Once you enter the URL and test, you will be able to see the URL has multiple prices and offers. This needs to be fixed so that Google does not get confused with the prices.