Your buying process may not be much about the final solution. For most Drupal firms like LightSky, the final solution is potentially anything you want it to be. We can build essentially any layout, any permission structure, any integration, or any functionality that you could imagine, with only few limiting factors. First is budget, and second is in some cases access to data.
Budget is a key part of the buying process. No one is going to go into a project like this with an open wallet budget, and no firm should expect that either. That would be a pretty big red flag. LightSky does all if its bidding fixed price. The problem with fixed price is that it is very feature dependant, and price or features will be a limiting factor. If you have a $50,000 budget you may have few limitations on features, but if you have a $10,000 budget, you might need to start smaller with a limited feature set and work your way up.
Knowing and understanding the features you want, helps solidify the budget, and being able to clearly outline those features can save you money. If your firm knows and understands what you want, they will be less likely to add padding into their estimate, and with a fixed price project that can make a great deal of difference.
Access to Information
This is another very limiting factor, but it is one that neither you or your web firm have any control over. If you are using a third party tool, and that third party doesn’t allow for access to that tools data, or essentially have an API, you aren’t going to be able to integrate that tool. You can have the best programmers, and the biggest budget, and it probably won’t change anything about this situation. So from a long term view, picking your third party tools carefully can save you a lot of headache down the road.
From a buying process point of view, be very clear about your integration desires from the get go. Don’t be vague about what tools your are integrating, and be clear about what parts of those tools you want to see integrated. It seems like every RFP we respond to includes a requirement to integrate with “our chosen fill in the blank tool”, and leads almost always to a question from the responding firms asking what the tool is. If you find out that the tool doesn’t allow for integration it makes a big difference. Also when you are using technologies like Drupal, an existing integration might save you thousands of dollars. Vague requirements can lead to a firm bidding on the assumption that they will have to write everything from scratch. The power of using open source communities such as Drupal is that isn’t always the case. Often times tools are built already and just need configured. Don’t back yourself into a corner by not giving the appropriate information.