This calculator is based on the rules in Aces & Eights section 5.5, Goods and Services.
The rules call for adding 5D4x10% to the base price in a gold or silver boomtown such as Lazarus, where easy-flowing gold tends to inflate all values. That effect is built into the calculator.
The rules also call for adding a substantial freight surcharge to the base price of manufactured goods, which must be imported from factories back East. The freight surcharge is 10% of the base price per 25 miles from the nearest railhead.
The freight surcharge does not apply if it's a good that's produced locally. It does not apply for services and salaries unless the GM says otherwise. If it's a good that must be brought in by train and wagon over hundreds and hundreds of miles before it reaches the store, however, check the "Imported" box to add the freight surcharge.
For the nearest railhead this calculator uses Cheyenne, in the Colorado Territory, as suggested by Kevin Innes in his unofficial but sensible Denver Express download, available at Killbeggar's Aces & Eights site. That puts Lazarus at 528 miles from the Cheyenne railhead, which adds 210% plus 5D4x10%. (Looking at the eastern railheads listed in the book for comparison, Lazarus would be 611 miles from Sweetwater and 752 miles from New Echota.)
This calculator does not use penetration dice (open-ended dice) because the coding was more of a pain than I thought it was worth.
Compiled by Shane Ivey for personal use only. Aces & Eights is (c) and TM Kenzer and Co.