I'm a bit of a bike snob. I admit it. But I bought a really cheap (new) fixed/single speed from
eBay about a year go. It is very bottom end, with unbranded cheap components. I changed the brakes for some dual pivots I had lying around the garage. Other than that, it's still exactly as it arrived in the box. The plan was to try it, and if I liked fixed to offload it via eBay and buy something better. However, it has never let me down and nothing has broken yet, nor does anyting look like breaking - although I did have to true the front wheel following a incident involving a carrier bag and a swallow dive over the front bars at dead slow pace. The wheel straightened up fine. So I've kept it and it serves perfectly well as my hack bike. Sometimes I even roll up the right leg of my jeans and pretend I live in Clerkenwell.
I guess my point is, it depends what you want the bike for. For me, it's cheap enough and practical enough for me to take to town, leave locked up with only a half decent lock and I don't have to worry about how much I'll lose if it gets pinched. As my hack bike, mileage is low. All of which makes it value for money in my book. And it adds variety to the fleet.