I'm living in Jordan and these are the current prices AFAIK. Depending on when you visit, staying in the village, the cheapest prices are around 20 JD/night, which may include a hot meal if your at the right spot. Staying in a camp in the desert can be similar priced. There are also lux camps in the desert (AC and jacuzzi) which can go for around 150-200 JD/night. Desert taxi will cost between 20 - 60 JD depending on distance. Hiring your own 4x4 from Amman will be between 60 - 90 JD / day + 20 JD / day park 4x4 fee. Falafel sandwich 0.5 JD, 1.5L of water 0.35 JD, chicken dinner at the restaurant 4 JD, sleeping in the desert 0 JD.
Does this cover it? Happy to help further if needed, recommendations for places to stay, guides, topo beta.