Plugging your device isn't hard, but wireless charging is convenient, especially when it doesn't cost much.
If your device is already Qi-compliant, you don't need a $40 wireless charger: this one works just fine at less than $6 (free shipping). Note: it provides 1 amp, so while it's good for phones, it's usually not enough for large tablets. It doesn't have magnets to put the device at exactly the sweet spot, but it doesn't take long to place it correctly by yourself.
If your phone doesn't support Qi (or wireless charging at all), you can convert it for less than $10 (uses your phone's USB port).
Wireless charging doesn't have much range, so a thick phone case (Otterbox or wallet-type case) will prevent it from working. Induction charging is also less efficient than running through a cable, so there's some power waste, but since phones don't consume that much power to begin with, it's unlikely to make a difference on your electric bill.