I think for any company to take an IS initiative into account ther has to be a very broad understanding of the business analysis. It is utmost essential to first find out how useful is the IS system to the firm. The bottom line is that it is not write to base such a decision on a financial model totally. We know that such systems bring along with them some tangible and intangible criterias.
Costs generally tend to be tangible whereas benefits intangible.
It is a known fact that costs and benefits do not occur in the same time. So i feel the whole idea has to be given greater consideration rather than just basing decisions on financial or capital models. I tend to agree with Yussra that we have to take the long term benefits into account. However an added fact is that this industry tends to outgrow itself at an alarming rate. In 5 years the same technology might be obsolete.