I wouldn't use trollandtoad as a guide for pricing Pokemon cards personally. Some of their cards are significantly cheaper than what they would typically sell for on Ebay, while others are significantly more expensive. I've also heard that the condition of their cards can be a bit random, with customers receiving cards advertised as "near mint" that look anywhere from heavily played to flawless.
You're better off checking Ebay. See what others are selling their cards for and price yours for around the same price or slightly less. You can also search for previously sold listings to get an idea of what people are generally paying for a specific card. This is particularly useful if you want to stick something up for auction.
Looking at your cards, I think you could probably get about £10 if you sold them collectively at auction. Or perhaps closer to £15 if you sold them individually. You have some desirable cards, but none that are super rare or valuable.