It's a nice cage at a good price and has a good deep base, and comes with a rat tube. I would also prefer side doors and not just top doors, and as the others say, Zooplus has some excellent cages for under £50. The Ruffy is probably much better built than the Alaska cage, but then the Alaska is only about £32 and has a big front door which gives good access.
Also I reckon the 100cm Barney is a fairly futureproof cage. I have an 80 x 50 cage and wish I had got a 100 cm one, as once you get the cage contents in there's not that much floorspace. If you were going to spend £50 I'd get the Barney (just under £50), unless you particularly like the Ruffy.
It's here _ you can also see reviews and photos of set ups on this link.
Barney Pet Cage | Great deals at zooplus!
Having said that, I quite like the height of the Ruffy (which is the same height as my Savic cage) of 38cm as it means it's easy to set up without fall risks, especially if you fill the base with deep substrate. On the downside to that, it's not easy to fit a shelf in as not enough space under the shelf to put things. Plus a Syrian sized wheel virtually fills it - which is ok but it ends up taking up a big chunk of the cage and floorspace and lowers the substrate in that area. I'd go for the Barney