How much per month to store freight cars?

I see some unused lines are used to store freight cars long term. How much do car owners pay for this?

Looks like all rates are negotiated and probalby depends on quite a lot of parameters (location, duration, type of car, how siding space the storing company has remaining, and so on)., but I was able to find at least one base rate:

For long –term storage (60 days or more) of empty non revenue privately owned railcars the following charges will apply:
Movement of Railcars from Interchange to Storage Track and reverse:
Inbound Charge………………………...$140.00 per car
Outbound Charge………………………$140.00 per car

Per Day Storage Fee…………………… $ 2.00

But if you had asked last spring, you could have gotten such a deal!

Limited Time Offer:
 Non-hazardous, empty railcars store for just $1 per railcar per day
 Switching fees are charged at just $125 in/out

I have seen the Class I lines use branches which have no current service as storage areas.

some of the now closed military bases that have rail in them are being plugged up with stored rail cars for the time being. I've also heard of a few RR's gathering older cars up and cutting them up for scrap rather than storing them as well.