www.amazon.co.uk/dp/B003LVIHFA may be the sort of thing you want. It's fairly low cost to purchase. Colour Toner cartridges do about 750 sheets. Full cartridge set I think is around £110 - hard to tell exactly as not sure exactly what model cartridges it takes. There are a couple of other consumables (imaging unit for example, which is replaced every 6000 full colour/24000 mono pages) that I can't find a price for - might be this at around £100. There is also a waste that needs replacement every now and then, which is around £12.
So calculate the probably cost for say 6000 sheets.
So toner: say 8 packs... £880
Image Drum: £100
Waste x 2: £24
So £1004 for 6000 full colour sheets = 16.74p per sheet plus the cost of the paper.
That is probably worse case situation, in everyday use you may well get toner lasting far longer as not all pages will be full colour but will be a mixture of black and colour.
A PoGo is low cost to buy (around £30) and sheets are about £10 per 70 so 14.3p each. Papersize though is 2" x 3" (5.08 cm x 7.62 cm) - so small photo.
A mono a4 laser Samsung for example is around £50 to buy. Then cartridge is around £50 for 1500 pages, so 3.33p per sheet. Waste and drum costs as above but drum replacement at 24,000 pages so a lot of printing.
You will also need to consider what access to the printer(s) you need. Ethernet printers will cost a bit more than USB. Wireless will again cost more (I'm not sure about that technology yet, reviews of wireless printers are rather mixed.)