I shall be in Nanjing 7-10 october next - are there any tours I could do, if so how much?

Yes, I know a trustworthy travel agency named Travel China Guide can arrange tours in the city. But I just consulted them that no group tours can be joined during your travel, but they can arrange great private tours for you. If you are still interested, here is their email for your reference:
traveltravelchinaguide.com