Both products are gonna set you back a fair bit, because Necromancers version of CSIO is worth as much as the original
JG versions, and the Wilderlands of High Fantasy from Necromancer is one of the best campaign settings out there. The cheapest way to get the wilderlands info is to buy the PDF from RPGNow. I don't know if they ever released CSIO in PDF, but if they did then you'll be cheaper buying that PDF too.
CSIO
JG 1st Printing - $60-$100 depending on condition.
CSIO
JG later editions - £30-$60 depending on condition.
CSIO (Nectomancer) - $60-$80 depenfing on condition.
WoHF
JG 1st Printing (Pts I & II) - $40-$80 depending on condition.
WoHF
JG later editions - $20-$50 depending on condition.
WoHF (Necromancer) - $75-$100 depending on condition.
It should be noted that the Necromancer reprint of CSIO contains both the original CSIO product and Wraith Overlord (the underworld beneath the city).
It should be nothed that the Necromancer reprint of WoHF contains also the contents of WoMR, WB and WotFR, the complete 18 map set.
Unless you have a particular need for the original
JG product, or are looking at investment and collectability, I would suggest the Necromancer PDFs, or the
JG PDFs are the best option. I can supply any of the above in near mint collectable condition, but would be looking to negotiate at the upper ends of those prices. The Necromancer PDFs are among the best PDFs available on the internet.
This week I've been mostly eating . . . The white ones with the little red flecks in them.