Yes, do take a look at their fees. There are a lot of pitfalls that could cost you extra. For example, you have to pay an additional 55 pounds or euros if you don't check in online but try to do this at the airport.

https://www.ryanair.com/gb/en/useful...lp-centre/fees

Also note that transportation to the city could be more expensive (or cheaper) as they often don't use the same airports as other airlines.