Based on the apparent smoothness of the casting and the probability that it is both domestic and old, maybe $15-20. If we were absolutely sure it's BSR (we cannot be, absolutely, without an original boxed or labeled example), probably double that. If you ask around, you're sure to get differing opinions as to the possibility. Until someone is able to present a tea size stick pan with the BSR loop style handles and markings, dismissing this one as a BSR impossibility seems presumptuous, as does assuming/insisting the catalog's single illustration must be representative of all the sizes. Here's what the ca. 1940 RM catalog listing looked like:

You can see that the cob size dimensions given differ from your rough measurements by just 1/32" and 1/16", and by a shade over an ounce on the weight, all close enough as to be insignificant, IMO. As to the overall size, note the legend says, well, "Overall". If you do the math, 7 cup widths is ~ 5.5", plus an extra 1/8" each (being generous) for the spaces between cups and at the ends, 8 x 1/8" = 1", so about 6.5" without handles. The 8" length description therefore must be

*including* handles. Similar calculations on the other sizes (the cob width typo on the 7-S notwithstanding) and measurements given by those eBay sellers who apparently actually used a ruler (on their 7-Ss) bear out the assertion the dims all

*include* handles. (note the 12.5" ruler)

Another catalog from BSR's sister company opted to round the weights to the nearest half pound when converting them to eaches, overstating and in one case understating the RM catalog dozen weights. The 7-S cob width error persists in that catalog as well.

One seen on eBay has the same inscription as yours but on a rightward-pointing ear and has three dots on the handle.