There is 3 primary costs, rack space, power usage, and data usage. The first two primarily have to deal with how much load there is and the amount of equipment needed to support it. The third portion is based on the data used and if it is in a peak/non peak time.
For a full 42u rack your looking at $500-$700 monthly for the space and drawing 48-72kw a day(so maybe $3.75-$4.50.) The data is a much harder one to calculate without knowing the specifics and it can skyrocket in ddos attack. These numbers are just based off of average hosting rates and on a fairly low industrial power rate. Also assuming that all the equipment is owned by Jim, the second you have to start renting hardware it goes up fast.
I do not know what he needs exactly, that just gives a rough idea what it costs per rack. The old picture with all the servers in the back of the car would probably fill 2 racks.