There is no point in wasting hard earned money on an expensive gadget when a cheaper one will serve the purpose just as well. This holds good for cheap used phones. Many people who stay at home like home makers, senior retired citizens or even those who work from home do not need a cell with too many fancy features. These people only need their phones for the occasional e call they have to make or for incoming calls.
All their other entertainment is taken care of by the regular gadgets at home like a music system, television and even a personal computer. Buying a new cell which costs them a pretty packet is really not necessary.
Those who have one cell at home may share it with the others and would need an extra phone only if they were travelling or away from home. This would be for a temporary period and it does not make sense to get a fancy cell for this short period. A cheap used cell would be the ideal solution here and you could get one which serves the purpose and does not cost the earth.
People who have domestic help at home often provide them with iPhones to enable them to communicate with the while they are away from home. Getting a cheap cell for such use would be a good bargain as you only need to make voice calls and not for any other purpose.
While visiting another town people may need an additional cell for the period when they are there and this would be of temporary use to them only. Why waste money on a cell phone with too many fancy features when you may already own one such mobile, the second phone for communication can be a cheap phone.