Selling By The Glass, Bottle and Retailing in a Wine Bar

[rain4st]

Hello everyone,
Well we have opened and are excited about the new business. I still have questions about pricing however. I have been using the price x 2.5 for the sale of a bottle (on premise consumption)and price x 3 divided by 5 (pouring 5 oz.)for the price per glass. I then sell the bottle (retail to go) at $4.00 off the "on premise price". *Reverse of corkage fee.* My dilema is that I believe my retail prices are too high.
Example.. Greg Norman Estates Cab/Merlot my cost is $12.75 per bottle. Per glass price is $7.75 and $29.00 per bottle (includes corkage fee). I have been selling the bottle to take home for $4.00 off for a total of $25.00. Although I have not had any complaints, I think I am too high on the retail end. I just visited Greg Norman Estates on line and suggested retail is $17.00.
The Greg Norman Estates is new to this area, so no one is able to compare price. However, I would like to build the retail end as well as the "on premise consumption" and do not want the public to think we have over priced the retail wines. This is only one example, but one that holds true for the other 40 wines that we pour.
Anyone else selling retail as well as on premise? Please help! If I price too low on the retail end the customers inside the wine bar may take exception. Anyone have an actual sliding scale for both retail and on premise?
Many customers are enjoying the ability of tasting and purchasing the wine for later consumption, so this point is very important.
Thank-you in advance for your help!