There is nothing like a great business that states they will offer you great things or even post comments that will draw your attention just to have you email them, dm them, or message them for details. What a turn off.
It is important that you have your rates and proposals set in stone unless you are offering a universal special.
Transparency is a key element in building your brand. No one wants a shifty business adventure. That is surely what you are telling your potential clients by being secretive about your offers and pricing. Will it be ten dollars for me and seven for Sally? Will it be twenty dollars the next time I order?
No one wants to be strung along and surely no one wants to play a guessing game when they are simply trying to buy what you are selling. Don't make business harder than it has to be. Post your business or promotion along with your site and let automation do the work. That is, after all, one of the joys of current technology.
Furthermore, why would you desire to spend countless hours responding to each interested party with "check your inbox" to only further exhaust yourself with putting the same message in each one? We have to learn to manage our time more wisely especially in the growing stages of the brand; that is the time that could be much better spent.
Isn't it time to work smarter not harder?