I have never experienced any hidden costs at SFC. I have asked for print outs of my account on a number of occasions and every time the figures have added up - apart from one accidentally duplicated entry which was found quickly - and the figures for my PPL, CPL and ME were roughly as estimated by SFC when I signed up.
Colin Dobney is an interesting character. He doesn't appear friendly when you see him wandering about the FTO, but one-on-one he is a decent guy. And I'll tell you something else, he's an excellent instructor too, with a surprisingly fatherly style, completely at odds with his public and 'test' persona, but he won't pander to your ego and will tell you when you've done something stupid.
As others have said, if you have a problem with Colin you'll have big problems in the cut-throat industry, and SFC is a pretty good bet when it comes to matching pounds spent to qualifications earned.