Cheap magazine printing

I am moving from black and white to a full colour A5 magazine. Of course the costs go up, so I have been doing a lot of research into possible printers, to keep the costs down as much as possible for the church. My present printer is Imprint, who produce an excellent product, but the move to colour will see the costs rise to a level which may not be affordable, given the revenue we get from advertisers. There is a company called Helloprint, with a London office but who are actually based in Holland. Their preliminary quote (including delivery) is almost half what I would be paying if I stick with my current printer. One of the reasons is that the printing is currently digital (i.e. a bigger version of home printers, using A4 paper) and the cheaper option uses the traditional litho method with large sheets of paper - which is better for large numbers, in multiples of 16 pages and 500 copies. Has anyone used this company who could share their experiences?
We've used Print carrier for leaflets several times - I believe it is a German company, but now has printing in the UK. They are cheap and efficient, but I've not used them for magazines.