It shouldn't be that hard to do! ( ...says me, who has never organized any events except Community Watch meetings and cookouts )
1. Ask everyone who is interested in a Knife Swap Meet to send a message indicating their interest.
2. Group the replies according to geographic location.
3. Determine which geographic areas have enough interest - I would think to be practical you would need interest from 25-30 people to make sure that at least 10 or more will show up - but I am not an event planner, so what do I know?
4. Ask for two volunteers from each geographic area with enough respondents to be the coordinator/organizers for that area. That way if one organizer has an emergency, health or work issue that interferes, the remaining organizer can find another volunteer to continue event planning and execution.
5. The two organizers look at the geographic location of their area, and determine a central or strategic city/location for the swap meet. Then they figure out which two to three dates work for themselves - remember, they HAVE to be onboard and present! - then present those two dates to all the respondents and ask them to pick the date that works best for each respondent, and whether or not they are willing to commit to attend on those dates.
6. If enough respondents are willing to commit to a certain date and location, find a venue in that city/location and determine the cost of same. Sometimes certain civic/government (parks and recreation, community center, etc), organizations (Civitan, Ruritan, Chamber of Commerce, churches, etc) or other groups may have low cost facilities available for use (daily rental or user fee).
7. If a suitable, affordable venue is available, take the cost of the venue and divide it by the number of respondents who have committed to attend, and ask them for advance payment to secure the facility.
--- EXAMPLE: 12 respondents. City Parks and Recreation Dept has a facility available that can seat 20 people and still have room for at least 3 or 4 standard 8'x4' tables for $75/day. $75/12 respondents = $6.25 per respondent. There is room for at least 5 more attendees, so 5 more slots can be sold for $8 each. If they all 5 sell, $40 has been recovered. The organizers could keep $10 each for their trouble, and the other $20 could be used to purchase bottled water and sodas (coffee?) for the event.
I am using the bare minimum numbers above. The more knifeknuts who respond, the less each one has to pony up to pay for the venue. Of course, you might need a bigger venue.... so...?
WILD CARD: If you can get an organization to provide you with a venue for free, or super cheap - JUST DO IT!
The above is just an example, but it shouldn't be THAT hard to do... if someone is a good organizer and really wanted to do it.
If someone decides to do one in my area, I'll sign up.