The Price of AI Functionality in Email Productivity Software: A Descriptive Analysis of Subscription Tiers and Feature Bundling

This descriptive working paper asks how subscription pricing structures and AI feature access differ across selected email productivity software products. We recorded 30 plan listings from 12 vendors' own pricing pages in a hand-picked sample, re-checked on 31 October 2026. Headline statistics use the 24 verified plans from 10 vendors, excluding 6 plans whose prices could not be verified. Among 14 annual-billing plans priced in US dollars, list prices run from $4.17 to $64.00 per seat per month (median $25.00); monthly and two-year plans are reported separately. Where both terms are printed, annual billing is priced 20.0 percent below monthly billing at the median (11 plans, 5 vendors). Of the 24 plans, 16 are coded as stating AI functionality, most often metered by credits or quotas (8) or included without a stated limit (5); 2 offer AI only as an add-on or integration and 4 do not state AI either way. No adjacent-tier pair meets the conditions for reading a price step as the price associated with AI access, so no AI price premium is computed; this is a finding about comparability. The analysis is exploratory and not pre-registered, and it makes no causal, welfare or representativeness claim. The author's company sells one of the products in this category and publishes the commercial price index from whose records the sample was drawn; its own product is excluded from the sample, and the vendors were not consulted. Version 1.0 is a working paper that has not been peer reviewed. Data and code: doi:10.5281/zenodo.23841631.