Shady peanut butter deals?

Finding food is one our biggest challenges for the Zimbabwe School of Youth Leadership. For the Z.S.Y.L. we ask all of the Salvation Army divisions to contribute by bringing food items. This means that the students of the youth leadership school can eat for the 2 weeks or 1 week that we gather. Unfortunately, most divisions brought cash instead. It's hard to eat money! Of course, in a normal situation, you could just take that cash and go buy your items, but although some food is finding its way back into the shops, there are still some very bare shelves. The other problem with cash in Zim is that is loses value every day. OK, to be precise, in Zimbabwe we don't actually have money/cash, we use bearers' cheques, but you know what I mean. John and I decided that we would contribute the peanut butter for the week. Peanut butter (dovi) is used in porridge, vegetables, etc. So yummy. There is an officer who is raising orphans and selling peanut butter to supplement her income, so we decided to buy our 16 bottles from her. The price was $7 million, but last Monday she only gave us 13 bottles and said the other 3 would be coming. Last night I went to go pick them up. "Sorry, the price has gone up to $15 million per bottle. Can you give the top up?" Now, this is actually not an unusual situation in Zimbabwe - the price of an item more than doubling in a week. But when you already paid and agreed for last week's price? Seemed a bit shady to me... Sometimes it's hard to determine what's "normal" here never mind what's "fair."