Also FastTech.com Some items are very inexpensive:
DHT11 1-Wire Thermometer/Hygrometer $2.55
HC-SR06 Ultrasonic Distance Sensor $2.26
16x2 LCD Keypad Shield for Arduino $5.85
20x4 Serial LCD Module Display $7.70
The free shipping got a bunch of items to me in 10 days so not bad from Hong Kong to Massachusetts.