When you build with bales, one thing is almost guaranteed: you will be plastering your walls. Knowing that, you may be surprised to discover that there is a cost that you should definitely put into your budget that may otherwise be overlooked. That cost is the electrical bill during the plastering phase.
Be sure to put in enough money to cover the cost of any heaters that you may use to dry the plaster, especially if you plaster during a cold or wet time of year. As an example, we used two plenum heaters in a 3200 SF house we plastered last month and the electrical bill came in at $650. That is a lot of money if you are no expecting the bill. A few little missed amounts like that and you will quickly find yourself in a financial hole!
Consider how long you will be plastering and estimate how much electricity you are likely to use. You may need to ask the local rental yard how much electricity the heaters you rent will use in a given day, or how much propane they will need to run. Over estimating is a good idea, especially with the rising cost of energy these days.