Does the $50 include postage costs? It might be more feasible to do more than one game. If you have enough pins for 60 spots, perhaps 2, 30-spot games, or 3, 20-spot games may go quicker. Then you can collect funds for the first game and start the second one, etc.
Or depending on how many lower level pins you have, decrease the price to $25-30 postage paid, have a 10-spot game where 1-2 pins are in the $50-200 range and the other 8-9 spots are in the $10-25 range? Then, repeat until you are done with pins.
Just cuz my 100-spot game took FOREVER to fill up (2 months and then 1 month for people to pick). Mad_For_Alice's 74 spot game never filled up (she had the designer villainesses as one grand prize and PODMs) so she stopped that game and created a new one with different prize levels, depending on how many spots sell.
That is another option, have multiple grand prizes with 1 grand prize available when 10 spots sell, a 2nd grand prize available when 20 spots sell, etc. (if you still want to do the $50/spot option)