This is a little bit difficult to answer because there might be 4 or 5 sizes of 1 animal but I got what I believe would be considered the medium size price. These are all from Shamu's Emporium, I would expect the price to be the same across all the shops.
The medium size for everything was $17.95, except for the penguin which seemed to be $21.95. Not sure if I could not find the medium size or if the penguins run more.
The next larger size for those animals with a larger size was $25.95. The larger penguin was $39.95.
I priced an even larger Shamu and it was $44.95, while I also found a different version of a medium dolphin for $16.95.
Right now they also appear to have a special where you can get 2 plush beanies for $20, just in case she could not decide between 2 of her favorite animals. If I get a chance I will get some pictures as well, but that might not be for a few days.