It depends on what you are tiling though dosent it.
£10 a sqm might not sound much, but if it's the kind of job where you can get 3 or 4 sqm an hour down then it's not bad money is it.
If someone had already had a quote from a new tiler who's still slow, but the floors quite big, say 25 sqm, but it's just mainly laying them down with little cutting, but the newbie tilers looked at it and thought "oh my god it's big, must be 4 days work for me", then quoted a day rate of £110 a day x 4 -£440, then you come along, know it'll take you 2 days absolute max and quote £300
It all comes down to what the job is and your own speed.