If you're trying to decide what pair of boots to get, but are tight on cash...then let me introduce you to the convertible boot. It's basically two boots for the price of one. It can be worn as an over-the-knee boot or unzipped at the ankle to be worn as a bootie (like the picture above). They have it at Victoria's Secret for $149 in black, ivory, brown and grey.
Where to Buy:
Convertible Boot, Victoria's Secret, $149