I ordered 40 boxes of 20 instant films from China. I take about 3 to 4 photos a day so this supply is going to last about half a year.
The parcel took 4 weeks to arrive. I ordered everything with the help of my friend Star through the Chinese marketplace Taobao. Taobao is a website similar to Amazon, but you interact and negotiate with the sellers directly using a chat client. You can negotiate, ask questions and arrange deals in real-time. For this reason it takes some time to find a really good deal. Star was chatting with multiple sellers and shipping companies for two days before placing an order. In the end the total cost of the order was 元4042.29 or £416.46 including shipping. The same order would have cost me £631.92 on Amazon UK.