The items that are half off are as follows:
Given the sale, I bought the Buccaneer's den for 5,000c. If I remember correctly, that just saved me 75,000g, if I were to buy it in game. Also, I have been sorely tempted to buy that 25,000g which I think was going for 6,750c, but have been able to resist so far. For some reason, buying gold in any game still has a bit of a stigma to me. I would be more likely to do it if I could trade it with other characters on my account. Oh well. I'd probably burn through it pretty quickly anyway and I tend to only buy things from the shop that I will use for a long time. My lobster mount is still being used and my Skysnake pet lasted 35 or so levels until I got the Jackalope. The house will last until I quit the game, I'd imagine, so a good purchase!