Where to outsource is the right question. I could write a word processor, but my company just buys me Microsoft office. My company could buy the software I wrote from an outsourcer, but we consider it a competitive advantage to do it in house.
Buying a product is different than paying someone to make a product for you. Since your company is the only customer for that product there is no benefit in outsourcing it other than the ability to rent a developer (contracting might be a better option). Nobody else is going to buy that product.
