Hi Mike,
It would not be “difficult”, but would not be quick & easy either. There’s quite a lot more involved than simply adding another field. It would certainly take much more time to implement and thoroughly test than the $50 I would lose if this is what’s holding you back from making the sale.
Of course, I can always be hired to do custom programming, and could create a custom version for you. I’m doing something for a large Canadian auto parts company where we have 5 different types of roles, each with their own pricing options, although in that plugin all prices are calculated based on either “list” or “cost” price, and a multiplier for each role type (and also individual users)… so, it’s quite a bit different in how it works than my wholesale plugin.
I get way too many feature requests, and have already made the plugin more complex than it was intended to be by doing the completely independent tax settings that a German client needed (and paid for my time to code those features).
There is simply no way that I can please everyone and put every feature request into the plugin, without it getting too complex and bogging the system down.
Right now I’m in the middle of working on version 2 of the plugin, which will greatly simplify some of the code, and hopefully improve compatibility with other plugins. Lots of changes in the newer versions of Woocommerce, plus some feedback from the guys at Woothemes, have helped me find some simpler/better ways of doing some of the tax stuff. That’s the main purpose of this next release — to refactor and simplify the code, as well as a few minor new features along with compatibility with WPML and some other plugins.
At this time I’m not considering adding any more features until version 2 is released and stable. However, please add any and all feature requests to that section of the forum here, as I do review those and may add features that I think will benefit many users in the future.
In the meantime, though, you may want to look at the Dynamic Pricing extension. Although that plugin is not compatible with mine (although I’m in talks with the developer to try to figure something out), it has much more flexible pricing schemes, including role/user based pricing and discounts, that may be closer to what you need. I don’t think it has the ability to hide products from certain users, but perhaps there is a way you can prevent certain users from buying certain products (can’t say for certain, though).
Sorry I can’t be more helpful right now.