Just because something is inexpensive, doesn't mean it is cheap.
It is highly rated on Baby Bargains and highly recommended on here by moms.
We have used the Gulliver crib with all three kids (new cribs each time, because we didn't want to waste space when moving). DS2 uses the Gulliver at grandparents house, and Sundvik at home. We use the Colgate Classica 1 mattresss.
I love it and personally wouldn't buy another crib other than the Gulliver/Sundvik. I don't see the point in spending $200+ on a crib, when the Gulliver half the price and just as safe. My sister did and regrets spending so much (chew marks, etc). Our Gullivers have held up great! I definitely recommend them!
And ignore any comment that says they are flimsy and wobbly. They are not. Of course the floor versions sometimes are, but there are hundreds of people in the store each day shaking them and messing with them.