The real question is how much processing grunt do you need, and does it have to be onboard or can you process it at the basestation after video broadcast? Simple ARMs are $10 or less. My cheap sourcing advice at hobbyist scales is to search for the chip model number on taobao.com and evaluate CNY prices. Most suppliers will ship overseas for a small additional shipping fee. Also, if you find a niche product (dev board, etc.) with a clear manufacturer, try contacting them through their website directly. Seeed is a well known and reputable source of popular parts who ship overseas.
