Good news: Short-term sublet prices drop in the summer.
Sure, you'll spend more on airfare to fly to Europe in July and August. But summer price hikes don't apply to lodging if you go the apartment-rental route. In fact, the cost of short-term sublets drops in the hot months, when Parisians take their own vacations in the provinces, putting their homes in the city up for rent. The surfeit of available spaces makes prices go down.
Classified ads websites such as Kijiji and Craigslist have powered this growing trend; now, intrepid French apartment-owners are using blog software to create websites for their pied a terres, with images, maps, and neighborhood tips.
Obviously, it is buyer beware when it comes to transactions with individuals you don't know. For the wary, there are several established companies for furnished sublets, such as Kudeta (kudeta-home.com), that are more legit.
--Laurie Pike, for our Affordable Europe series.