Actually, buying new will stimulate the global economy a lot more than used purchases - so patronize the new equipment dealers in the classifieds! (Of course if you are looking for the red dot brand, there are no new items, so used is the only way to go, diminished stimulus and all)
This is pretty political but...
Not really. Sorry. False sense of stimulation. The only way this works is if significant amounts of money is produced and circulated among the lower classes. Ultimately it de-values the money and products (these days in a hurry). However every time the money moves -even if it is from you to a local camera shop, to Lecia- , everyone single time, money flows up and into capitol of rich that only invest it to take more capitol from people. If money doesn't come down from the top investing in things that are good for communities, points of pride, then nothing changes but our illusion.
You may believe previously in history that the economy was stimulated by people buying things. In a way it was... However that excess capitol for stimulation is now debt. Essentially you see an influx when money tied down is circulated by deregulation. As we now know though, it all gets sucked up into the major players as we "spend out wealth cause it just comes at us".
Technically what you want to do is circulate local money as much as possible with used things of value. You keep this circulation rate high and it redefines the value of new things. Those with, will invest and invest, and fail because local circulation is stronger and their products ultimate worth is low. They will throw money at it, or end up spending money while not making. That will increase the amount of not-inflated money circulating in daily people's hands. Currently the issue is we are rather not "allowed too" do this because when those trying to take all our capitol sense this situation you get retaliation of law. You see things like FBI raiding raw milk clubs. You see new standards for the food industry that force out competition. New ways to transact money, new coupons, new press releases about how the local people are "ripping you off" by charging "too much".
You can imagine how hard it is to get the ball rolling since it is essentially illegal, but do you think the next crash will be better or worse than this one?