As has been said and alluded to already, there really is no good set of rules that will satisfy, or even function as intended, across all the possible life scenarios. In the example of a widow or neighbor getting out of woodworking and selling their equipment, it makes absolutely no practical sense to tell them they will need to wait six months to a year, post dozens of relevant posts and visit the site (login) 3+ times a week (etc.) before they can sell the equipment (especially if they are not an active woodworker themselves). For every seemingly good and well thought out rule one may wish to impose there are equally valid cases that immediately bring to light how absurd or unfair the rule becomes in other very real everyday life circumstances. Yet, it is impractical, and a major headache to implement, a site where we would have one set of rules that apply to most everyone, and yet another set of rules that would only apply to other select people (without even touching upon the perceived fairness and arbitrary nature of such, much less the headaches trying to maintain such). Meanwhile, other possibilities would require wholesale recoding of third-party software and all the time and investment associated with such (remember, none of us are paid for our time maintaining this site, so time must be allocated wisely and with respect for our Staff's personal time so that we are not monopolizing their free time for little or no real added benefit) -- there are many things we could do or change just for the sake of doing them, but if they offer no value-added benefit then they are likely a poor allocation of a limited volunteer resource.
That said, any ad posted by a new member who has been with us for less than 2 months is clearly indicated as such with a "New Member" banner in bright yellow just above the price and the member's join month and year are visible in the right-hand sidebar of the item's sale page specifically to call attention to the fact that they likely have no established reputation on this site (and to proceed with caution -- I added this feature to better inform buyers). While we could just outright and universally ban all sales by new members the result is that our members ultimately miss out entirely on those opportunities and it can make our community come across to the public as very insensitive (particularly in the eyes of widows, which is not especially uncommon in this hobby). Is it better that all such opportunities be left for the local CraigsList or Goodwill where very few of us will ever have the chance to see them?
As for high prices, many sellers believe their used gear to be made of solid gold while most buyers would rather pay solid lead prices -- it is not until that gulf closes in on a more reasonable valuation that a sale will take place -- and that is true whether they are a newly registered member or a long established member as such perceptions are fundamental to human nature. In virtually every hobby forum with a classifieds section you will find sellers advertising their used gear at greater than current retail prices, such is not usually a scam or an intention to cause harm, it is simply an unrealistic perception of value by the seller because most sellers suffer a cognitive dissonance when it comes to recognizing depreciation and/or the non-universality of sentimental valuations (especially in the case of a death). Others simply have no idea what an item is realistically worth and simply look for like items on the internet (often on retail sites, and some eBay ads can offer absurd values) and blindly use that for their valuation because they know no better and are naively pricing used gear. In time they will either come down to a more reasonable valuation, eventually enabling a sale, or they will give up altogether and/or move on. Nobody loses out in such cases, though their are no winners either until a sale can be made and everyone, hopefully, comes out a winner. Similarly, if you feel a price to be unreasonable you may always elect to make the seller an offer more inline with your own valuation, which they may either accept, reject, counteroffer, or simply ignore.
We do very much appreciate our member's input and use such for guidance in designing the site and debating the merits of rules and rule changes. However, it is also necessary to recognize that there are no truly fair ways to write certain rules that are ultimately very arbitrary in nature and, as such, we must chart a path that does the least overall harm and the most overall good. Sometimes the effort to create such well intended rules can result in very unwieldy policy with numerous rules amended by numerous exemptions meant to try and address all the unintended consequences of those well meaning rules. Sometimes the best you can do, instead, is try to create a very simple and basic set of rules that apply equally to everyone, only expanding upon such rules if absolutely necessary to address serious problems or abuses that cause actual harm and handle certain extraordinary instance on a case by case basis as necessary -- if nobody is harmed by a given act or example then is the rule, and its unintended consequences, truly necessary? That is the course we must invariably attempt to chart and it can be a real challenge because often there is no one course that will satisfy everyone! I thank everyone for their thoughts and understanding on the matter.