Typically not that little in bulk, unless you stock your own entire soda machines with syrups and carbonation systems and such. If you had people stocking up from sam's club or a similar 'bulk' store, you'd be looking at per unit costs of 25-60 cents per bottled/canned drink, depending on size.
Coffee - not as familiar with the economics of coffee, but of course dedicated machines will end up costing somewhat less than going directly to starbucks.
And most Cokes in a convenience store are now $1.50 or more, at least where I live.
Let's say 50c per soda. Even if everyone drinks 6 sodas a day you're looking at an increase of $900/year/employee. Call it $100k/year for an engineer and you're talking less than 1%. And that's 6 sodas a day, every day. I bet even with free sodas you average maybe 2 a day.
And if you have an entire team of engineers drinking 6 sodas per day each, your health insurances will balloon (as will their waistlines) in the next couple years.
It's amusing, because a 2L from a supermarket is the same price as a 20oz from a convenience store. Clearly the price is not driven by the cost of the soda.
In the case of Coke, I think the cost of packaging is bigger than the cost of the product, but either way its almost irrelevant to the price - they charge what people are willing to pay. I wouldn't buy a big bottle from a convenience store, a small bottle is more convenient for walking around with. I wouldn't buy a small bottle from a supermarket, I want a big bottle to put in the fridge at home.
Typically the smaller ones are also refrigerated whereas the 2L aren't, precisely because you're expected to grab the former when you're on your way from A to B and are busy.
Coffee - not as familiar with the economics of coffee, but of course dedicated machines will end up costing somewhat less than going directly to starbucks.
And most Cokes in a convenience store are now $1.50 or more, at least where I live.