Furby Boom Polka dot toys are available at a variety of places, both online and at brick and mortar stores. ToysRus has them available at the price of $54.99, ToysRus has both an online retailer and local stores. Target and Walmart both are selling the toy as well.
You should check out www.freecycle.org. This website has items on that people are giving away because they no longer need it or want it. You will have to register for your city, but it is completely free to register and use. Another good website is www.craigslist.org. where there are also free items listed and for sale items. You can also post on craigslist.org for items wanted.