Welcome to the forum Needawin. I myself will be a pensioner next year as I retire from active employment. The hobby can be as cheap or as expensive as you wish. There are ways to minimize original costs such as buying used equipment from places like Craig's list. There are also ways to minimize ongoing expenses by doing things like keeping fish that do not require a tank heater in a normal home. I have lots of those from a group called goodeids but there are also other groups of fish that do fine without a heater. In most setups, the heater and lights are the biggest ongoing expense. If you eliminate the heater and reduce the lighting need by avoiding plants that need artificial light added, you will have a fish keeping electrical bill about 10% as big as a person with tropical fish and lots of plants. Filters and air pumps are almost free in terms of power use.