Use something like HP Photosmart C5180 all-in-one.
I use this because it doesn't fuss when I use compatible/refillable inks. Buy the printer then buy empty cartridges and refill inks (search Ebay). It's a doddle and costs very little compared to the over-priced HP offers. Just follow the instructions. I have several printers including Epson large-format photo-printer, but use the HP as an everyday printer/scanner.
I bought this machine as advised by a (now retired) printer repair expert. He was right! No problems with this machine after many years of use. It's probably out-of-production now, but you could probably find one locally or on Ebay. My method is to find he cheap compatible cartridges first, then source the printer that uses them. Your children will be printing to their hearts' content without you going crazy!
NB. Remember to source good paper - it makes a huge difference between OK and great prints! Don't be fooled by advertising - I have found excellent stock at computer fairs and car-boots, I use this stuff professionally!
Hope this helps,