Um, the cost of running a printer is generally in proportion to both the cost of purchasing the printer and how much you use it and what you use it to print.
If you buy a £40 printer and put 100's of photo's through it, then it will be ruinously expensive compared to a £100 printer, as the business model the manufacturers use for the £40 devices is to make money solely on consumables, whereas more of the profit is derived from the cost of the device on more expensive models. This is true irrespective of manufacturer, although there will obviously be some variation in precise costs. This is also the reason each manufacturer has such a huge range of cartridges - each one has a different cost per copy ratio (or cost per ink capacity).
Basically, the cost per copy decreases as the cost per printer increases, and vice versa.
Based on this, rruwalton, you need to know roughly how many photo's the printer will be used to produce - if it's just 1 or 2 in any given month, a pretty cheap printer is likely to be the most cost effective, but if its 10 or 14+ per month, a more expensive one will be better.
You also have to bear in mind that when manufacturer's include the number of pages a cartridge will produce, it is based of 5% coverage (in other words, approximately the coverage of a full-page letter) - a photo is obviously a much higher coverage, so the no. of photos that consumable will produce will be a lot less than the stated number, which is based on a letter.
There are ways to reduce these costs though. I use Cartridge World (
www.cartridgeworld.co.uk) to refill my manf. original cartridges - you can do this 2 or 3 times without significant loss of quality.
Also, there are services on the web which will professionally print photo's and send them to you. Costs can be around 19p each I believe - I plan to try out one of these services when I have enough pictures stored on my camera. When you take into account the cost of photo-paper, ink and postage, I thinks that's pretty good value.