That is a very good, realistic question. Many times a farmer gets stuck between renting machinery or buying it outright. Purchase does not always make sense. If you are going to use a huge berm plower only a couple of times a year, just hiring someone to do it for you might make more financial sense. Or sometimes a particular specialized implement simply is not available for hire, and you have to buy it, if its utility is critical to you. Its not cut and dry as buying a bond paper unfortunately. This is real and honest line of work. :) Necessities will dictate what to do most of the time. Most implements gets underused anyway. Try to make do with what you have first, see how it goes.