Near Zero Cost
A "zero-cost" or "near-zero-cost" project utilises the materials and resources that are to hand or readily available for "free" or for pennies.
This subject has a major focus on accessibility.
Of course, there are very few resources that are actually free (in all senses) but at a resource centre such as the HackSpace there are many materials and donated items that are immediately available for use. This style of project development favours multiple-prototypes as better materials become available. This differs from a true "Instructables-friendly" project that requires materials that can be easily obtained from national chain stores like Hobbycraft, B & Q, or Home Depot in the USA.
There are pros and cons to all forms of engineering (and dare I say production of art?) and no form of engineering is absolute - we are free to mix and match. Some of the aspects of this form of engineering that could be considered "cons" are actually "pros" if viewed in a positive light: -
Abandon ideas of "value" -- enjoy a project for the failures that are made and the experiences learned. My spare time has massive value but I'm not going to try to monetise it in my hacking fun - not even think about it! There are all sorts of "costs" associated with formal engineering and especially with the prototyping phase ("everything is a disposable prototype"). Much of the ideas of non-recurring engineering (NRE) costs do not take into account the enjoyment of solving the problem and the aesthetic pleasire of a thing made -- the true reason why the person is an engineer/artist in the first place!