Thanks, Cubits, I'll have a read. I know I'm probably underpriced, but even at the prices I am at, I still get people saying they can't afford it.
I did raise some of my prices recently. Not all of my items would need higher prices, but a larger proportion would.
Bugphobia - I'm worried that people would view it badly, but I wouldn't raise my prices during the Heartsy deal. Definately shows the seller in a negative light. Those sellers must not have done the maths before the deal.
bumble, percentage of profit is a good idea. I add precentages when I do my pricing. I realised that I'd been doing it wrong for ages, and was undercutting myself, which is why I had to raise prices the first time. :/