I don't know if this is the right place to post this sort of question, so feel free to move it.
Lets say that Vendor X is selling a certain software package. There are also other competitors, including Vendor Y, selling similar software packages. My company is leaning toward purchasing the software package from Vendor X, probably due to our long working relationship with the vendor.
For various reasons my company requires a certain software feature. Vendor X's software package does not include this feature, but Vendor Y's software package does. This feature has nothing to to with our company or environment, but is a general feature that other companies with similar needs could also benefit from (which is probably why Vendor Y offers this feature as standard).
The quote given by Vendor X for the development cost for the feature in question was a little high. Also Vendor X's package is newish, whereas Vendor Y's package has been around a long time and has many customers. I am in favor of using Vendor Y's package, but most most other people prefer Vendor X's package most likely due the past working history of our two companies. I have a feeling that in the end Vendor X's package will be chosen regardless of the cost. Given this, I want to try to get Vendor X to reduce their estimate to minimize the blow somewhat. (For the record, we have not yet received an estimate from Vendor Y even though we have been waiting months. There is some potential weirdness going on, but for the sake of simplicity I won't elaborate any further.)
Would it be unfair or unusual to ask Vendor X to reduce, or possibly eliminate, the development cost for the feature that arguably could be used to add to the overall desirability of the package in the software market? Is this an atypical thing to request? BTW, we asked casually about this once, but the vendor said no. (I have a feeling that Vendor X is aware of their status as preferred vendor and so is using that to their advantage the best they can.)
If Vendor X does not budge on the development cost, would it be impractical, unorthodox, or maybe even crazy to require that the vendor not to use any of the code used in the development of our custom feature in the standard package that they sell to other customers? How would that even work anyway?