“Mismatched value (page crawl): price” is one of the most damaging errors in Google Merchant Center: Google crawled your product page, saw a different price than the feed declared, and disapproved the product (its price attribute page states the rule: the feed must match the landing page). Enough of these and the whole account gets suspended. The good news: nearly all mismatches come from four causes, all fixable.
Cause 1: a stale feed
You changed prices in the store, but the channel is still reading yesterday's file. Any feed that's uploaded manually or rebuilt on a slow schedule will drift out of sync (on WooCommerce the culprit is usually WordPress cron) — a weekend sale is enough. Fix: make sure your feed regenerates automatically after price changes, and that Merchant Center fetches it at least daily (Settings → Data sources → fetch schedule). If you run flash sales, hourly is safer.
Cause 2: sale prices in the wrong field
Google expects the regular price in price and the discounted one in sale_price. Feeds that overwrite price with the discount — or send the sale in price and nothing in sale_price — mismatch the moment the promotion starts or ends. Fix: map your store's “compare at” / regular price to price and the current selling price to sale_price, and let the feed carry both.
Cause 3: currency and tax differences
The feed says €49.00 but the page shows 245 lei, or the feed is net of VAT while the page shows gross. Google compares final, as-displayed values in the same currency as the landing page. Fix: feed the price exactly as the customer sees it on the page for the target country — currency included. If you sell to multiple countries with different prices, each country needs its own feed with matching values.
Cause 4: “clever” feed rules that touch price
Some setups apply transformation rules to the price field — rounding it, adding a margin, syncing it from a spreadsheet. Every one of those is a mismatch waiting to happen, because the page never changes with it. Fix: treat price as untouchable in your feed pipeline. The feed reports what the store says; promotions happen in the store.
How FeedRobin handles it
FeedRobin syncs price changes from your store within minutes and rebuilds feeds automatically, maps regular and sale prices to the right fields, and — by design — no rule can ever rewrite a price. Whatever your store reports is what every channel receives, so the page and the feed can't disagree. The free feed check opens a sample of your product pages and compares the prices it finds with the feed, before Google does.
Sources
Google Merchant Center Help: the price and sale_price attributes, and the full product data specification.