Many bottle collectors get started with bottles such as the lovely cobalt blue Bromo Seltzer. Who doesn’t like cobalt blue?
Yes, they are common but there are hard to beat for beautiful blue glowing in your window. Get a plain cobalt one for just a few dollars. There are teal blue and Prussian blue colors around but they are more scarce. You will need to pay more for them. Occasionally, you will see a very pale blue example that borders on a blue aqua color.
This set of 3 Bromo Seltzers shows the different colors. See them at ebay.com

Colors of Bromo Seltzer bottles
A few Bromo Seltzer bottles at auction on ebay
You will see a wide variety of prices and conditions. Be picky. These bottles are fairly common, so hold out for a decent price and look for examples in clean, undamaged condition.
Age of Bromo Seltzer bottles
First, cork top examples are always older than screw top. Figure that screw top glass bottles could be as new as the 1960s. For cork top, many will have a mold seam that goes all the way to the top of the lip which indicates they are made by machine (known to bottle collectors as ABM which stands for automatic bottle machine) A smaller number will have a mold seam which stops somewhere on the neck. These would be the earliest of all and date most likely before 1920.
Value
Cork top examples in perfect condition bring from $1 to $5 at online auction. Expect to pay more for unusual colors – perhaps as much as $20 to $30. As of the writing of this article, groups of Bromo Seltzer bottles had also sold on ebay. I found one listing for a group of 14 that sold for $33. Note that these prices do not include the cost of shipping. Screw top examples are generally worth about the same or less. Labels always add value if they are in good condition, especially to the oldest cork top variants.
Photos of Bromo Seltzer bottles, advertising and related items

Bromo Seltzer promotional sheet music circa 1900

1949 ad for Bromo Seltzer featuring Mr. Percent

Bromo Seltzer ad from 1960 - still featuring glass bottles



i like online auctions, they give that sort of adrenaline rush when buying…