The sale and distribution of alcoholic beverages in Idaho is regulated by:
Alcohol Beverage Control Bureau
700 South Stratford Drive STE 115
Meridian, ID 83642
208.884.7060
http://www.isp.idaho.gov/abc/
Access to the full Idaho ABC Code can be found here:
https://legislature.idaho.gov/statutesrules/idstat/title23/
The sale and distribution of alcoholic beverages in Montana is regulated by:
Alcohol Beverage Control Division – Montana Dept. of Revenue 
P.O. Box 5805
Helena, MT 83680
406.444.6900
http://mtrevenue.gov/alcoholic-beverage-control
Uniform Pricing
Idaho: No volume discounts are allowed within the state.
Montana: Channel Pricing, Quantity Discounts, and Pulse Pricing are allowed within the state.
Wine and Beer Tasting
Idaho: Wine tasting is permitted in retail accounts. As of July 1, 2014 beer tasting is permitted in retail accounts.
Montana: Wine and Beer tastings are not legal in off premise accounts. It is only legal to taste in licensed, on premise accounts.
Supplier Licensing
Idaho: Out-of-State Beer Suppliers must obtain a Certificate of Approval license from the Alcohol Beverage Control Division each year, at a cost of $100/yr. Wine Suppliers aren’t required to have a certificate or license to supply wine or low-proof liquors.
Montana: Both Beer and Wine suppliers and importers must obtain a Certificate of Approval from the Alcohol Beverage Control Division each year. The initial license fee for either a Beer importer or Wine importer is $500, with a $200-$500 annual renewal fee.
Price Posting
Idaho: Idaho is a price posting state. The Alcohol Beverage Control Division requires that prices from the wholesaler to the retailer of all products that fall under the beer and wine laws, be posted on the Division price posting website. A link to this site is found on their website at www.isp.idaho.gov/abc . Price changes must be received, on the price posting website, no later than 10 days prior to the last day of the filing calendar month, becoming effective on the first day of the succeeding calendar month. If a posted price is lowered, that price may not be changed again, either up or down, for the next six (6) months. See Idaho Codes 23-1029 & 23-1329 for more details on price posting.
Montana: It is not a requirement within the state of Montana to post beer & wine pricing with the Alcohol Beverage Control Division.
Aid to Retailers
Idaho: Idaho has a Comprehensive Aid to Retailer section in its alcoholic beverage code. Among the regulations that are specific to Idaho and/or exceed the Federal requirements of the Bureau of Alcohol, Tobacco and Firearms is the prohibition against providing retailers with wine lists, exterior signs, credit, equipment, refrigeration, uniforms, etc.
Montana: Montana has a Comprehensive Aid to Retailer section in its alcoholic beverage code. Among the regulations that are specific to Montana and/or exceed the Federal requirements of the Bureau of Alcohol, Tobacco and Firearms, is a limitation of exceeding a $300 max value of functional advertising matter, in 1 calendar year per retail establishment.