The crude oil prices can be described as a very variable. In 2011 the market prices were often above 100 USD per barrel and at the end of March 2020, the prices were around 20 USD per barrel. The reason of such a large difference is, that there are more factors affecting the oil price.
Oil producing countries have also different marginal costs of oil production, so when the market price is for example 25 USD per barrel, some countries are competitive, so they are able to make profit and some of them not. The price around 20 USD per barrel is considered as a very low. When the demand will increase, it is expected that the prices will rise.
I would say:
Low crude oil price is bellow 40 USD per barrel
Average crude oil price is between 40 USD and 70 USD per barrel
High crude oil price is above 70 USD per barrel