Correct my math if I'm wrong. There were 8 months x 4 + 2 months with 5 weeks = 34 sets. Each set sold for $15 and came with one base set and two chase cards. Other than May, each chase was probably equal in value to any other. So technically you could trade one for one for the chase you got for the one you didn't get in the set. So I would say 34 x 15 = $510 + $50-75 for each of the May Wonkys you didn't get by buying one set. I used this philosophy of buying one each week and got one May Wonky.

I bought one set each week, did very little trading, and paid an average of $7 for whichever chase I didn't get. Leaving out May, there would be 30 x 2 x 7 = $420 for the chases. The base sets should be plentiful and low in demand, so you might get all 34 at $5-10 each for a total of $170-340. Using this method, it gives a range of $590-760.

So I would think a good price would be in the range of $500-750 + the May Wonkys.