Let's see. A roll of Velvia costs about $6 if you buy bulk. It takes about 4x4x5.5 cm, so you get 11 of them in one liter of space. Assuming you buy an efficient one, a small freezer of two by two by three feet has a volume of about 150 litres. Assume you actually use about half of that space, you can get about 800 rolls of Velvia in there that cost $4800. A freezer with good efficiency (class A+ or so) of that size costs about $700. Finally, figure out how long these 800 rolls of film will last and check with your utility company how much the 200 kWh/year of electricity cost; it won't be much, but it adds up.
You have some running costs and investments into the computer, but you're likely to do those anyway. Also you may need to invest in hard drives etc. or in some kind of backup solution (I use Ultrium 2 tapes that are standardized enough that they will be readable in 40 or 40 years and that hold 200 gigabytes each for about $20), but the film also wants to be developed and processed. However, if you have a moderately high usage of film, the M9 may well be more cost-effective, just like any other digital camera out there, which is one of the reasons why they are successfull with people with a high throughput.