I bought a coop from mypetchicken, built it and hated it. I don't have the time to build my own, so I bought one from a local shed company. It's much more sturdy than that flimsy thing I bought. It felt like it was made of balsa wood. That is not going to stand up to our predators and weather. It was also so small and they said it was rated for 6-8 hens. I wouldn't have felt good about putting 3 in there. I think it's worth it to invest a little more to get something substantial and big enough. Luckily, I was able to sell it for not much less than I bought it for.
In other words: store bought coops aren't great. They may be a temp stop-gap, but I wouldn't want my five hens living in it for an extended period.