The Mews booking engine (Distributor) displays rates based on rate groups.
If more than one rate is available in a rate group, the more expensive one will be displayed as a crossed-out amount above the lowest-priced rate (if there are more than 2 rates within the group, the most expensive one will be shown).
See the example below:
This is how the rate group is set up in the settings within Mews used in our example:
The most expensive rate being the Non-Refundable rate test the price appears crossed out and the cheapest Euro Currency Rate appears as the actual price.
If you want to show all your rates in the booking engine, then they need to be created in their own rate groups.
See below guide with detailed explanation on rate groups: