And 11 GBP?
That sounds a lot to me even for a big one. Then again I haven't checked ever yet what they take for them here, there are so many unwanted ones you can always get some for free cuz every beginner aquarist gets two and ends up with way too many, lol. No chance to find anything in the local classifieds or so?
They are cool though, mine are out most of the day even though they have plenty hiding spots. Very true about the spines, I usually try to catch them with my hands if I have to. Last time I used the net I had to cut it off the fish to avoid ripping all those spines out.