Actually, with several notable exceptions, pins on eBay sell for about what it costs to make them new. The last time I checked, a new, standard, 10K badge from my fraternity costs $45 plus shipping. The average eBay price over the past few months for our standard badges has been about the same. Interestingly, our sweetheart pins--which are not badges at all, even though they look like they are--sell for lots more because they tend to have pearls or gemstones in the perimeter.
OK, maybe you'd rather have YOUR pin melted down

than in the hands of a collector, but what if we were discussing one of your founder's pins? Would you rather have it destroyed than preserved and cherished by someone who just happens to have joined another group? Once it's gone, the best you can hope for is a reproduction, even if you used the same gold. But that badge your founder actually pinned to his chest is gone forever. What if we're only talking about a century-old badge? In those days many brothers found their own jewelers to manufacture their pins and the results were some stunningly beautiful, unique badges. By following your argument to its logical conclusion, you'd rather have them melted down than in the hands of a collector, too. (Continuing to follow it to absurdity, how do you feel about burning books?

) Case in point: There are seven more founder's badges from my fraternity out there somewhere. Unfortunately, after this many years of hunting--and believe me, I know brothers who have been searching our founders' descendents exhaustively--we have to accept the notion that they are likely distributed through a number of wedding rings by now. What a waste. If one were in the hands of a collector, at least we'd have a good chance of getting it back someday. Upon sufficient application of funds or (horrors!) another fraternity badge to trade for it, maybe sooner than later.
Furthermore, you may feel this way about your badge as we discuss this now, but unless you continue as an "active" alumnus, I bet you won't even be able to find your badge on your 40th birthday. I'd love for you to prove me wrong, but I am one of only five advisors for my chapter out of well over 300 living alumni. Most chapters on our campus have only one or two; a couple have none. Lots of brothers show up for football games or formal, but far more don't than do. We don't even have a current address for about 50 of them. If your chapter isn't like this and is at least 30 years old, I applaud your due diligence and hard work. Statistically, however, fraternity life after college is pretty thin. I wish it weren't, but on the far side of that sheepskin is the real world and I'm not talking about MTV. It is quite difficult to keep alumni interested once they get married and have kids. Those pins migrate to the back of the jewelry drawer and the offspring have no idea what they are. That's why dad's badge gets listed on eBay as "Sorority Pin". When I was "active", I remember very clearly one brother bemoaning our lack of alumni support and his claims he would always be there to help out. I haven't even seen him or any money from him in years, despite the fact that I have personally telephoned to invite him to participate.
I didn't mean to meander off the topic this far. But if people would put a tenth of the effort they expend whining about collectors into actually finding, contacting, and rerushing their alumni, the fraternity museums would be hard pressed to pay the insurance on all the gold.
Now go read the fable about the dog in the manger.