Should I find my own kitchen fitter?

Hi, I did a kitchen design today with B&Q. Kitchen cost around 3000 Fitting was estimated between 4000 and 5000. Is it more expensive to supply & fit with them than finding my own filter?
The sales guy also said tiles are really expensive to fit, would I be better off with splashback walls?

if anyone has any recommendations for good fitters in ashford Kent too

thanks