Who in the European LCC market really have the lowest costs and price - comparison

Never mind what Ryanair states in their annual presentations about the cost and price differences of the market. These umbers are usually adjusted for a purpose and often do not reflect all of neither revenue streams nor costs.

A quick calculation of the 2019 numbers gives:
(All numbers in Euros and per passenger)

Company  -  Costs  -  Average Ticket Price

Ryanair:  -  51.5  -  59.4
Wizz:  -  60.5  -  69.0
easyJet:  -  70.0  -  74.0
Norwegian:  118.5  -  116.0

So even though Ryanair's comparisons have the right order they do understate what is their average price for a ticket. And the difference between that and Wizz's cost are not that much. If the last grew to what Stelios says is the ideal size of 200 planes they could very possibly fight very competitively with Ryanair on a cost basis, as long as they stick with the concept. Ryanair is upping there's with constantly adding additional paid for service that increases the true cost of flying with them

Norwegian on the other hand had even in a good/normal year serious problems, loosing money on every passenger they flew. One should however not read to much into the considerable difference in cost/price per passenger since they include long haul routes.