c# Advanced word editor facilities development using third party component

This is a preliminary step to evaluate the project. My need is to develop (using a third parts component that integrate all MS words facilities) a Business Layer as well as a GUI to inteoperate with the components. Primarly should be developed a BL to encapsulate all the component facilities in a OOP way, secondarly the software should offer some specific feature of an advanced word-editor. The main goals (apart of the integration) of the software is to compose words-like documents that user can write by himself as well as create starting from some saved templates (that software should be able to generate) and build a final merged doc for ROI (Request of Investments). For example the preface doc, or the product offering, or the technical specification. Build indexes, mail mergings. (All feature that component offer). In the major parts of the case the doc should be write once by the user and saved as template. There are a small part that should interact with a database for products, where users should be able to fill the product available (filling name, descritption, price, etc) and another area where user can build the template or the final doc, where choose products and put into the documents. Certain area of the finished document should use the word-table as well as the word style (that component offers) and that should be manipulable by the GUI (this make parte of the component integration). The component that should be used is TE Edit Control for .NET by SubSystem ([login to view URL]) A small project budget has been selected, but as I said, we are evaluating the effective costs and I'm interested also in your cost/opinion.