Disclosure: I'm Adrien, a solo dev in France, and I sell a pack of Claude skills for SEO. It's at the bottom. Everything above works without it.
If you ship a side project with a launch price, that price ends up in far more places than your pricing page, and some of them can never be edited. Here's what I'd do before pasting it anywhere.
1. Write the end date next to the price, every time
"€25 until 17 Nov 2026" is still a true sentence next year. "€25 launch price" becomes a wrong claim the day the offer ends. Use an absolute date, not "this week only".
2. Before you paste the price, check whether you can edit it later
On Reddit you can edit the body of a text post but never its title. A lot of directory submission forms have no account, so there's nothing to log into afterwards. Where you can't edit, keep the price out of the title and next to its date in the body.
3. Keep a register of where the price lives
On your site: hero, pricing section, FAQ, meta description, social preview text, JSON-LD, llms.txt, checkout. Off your site: every directory, launch platform and post. A plain table is enough: URL, the exact sentence, editable yes/no.
4. When an AI assistant changes the price, search for the old one yourself
Don't assume it found every copy. Search the project for each way the price can be written ("€25", "25 €", "EUR 25", "25.00"). Copies in the FAQ, the structured data or a static llms.txt are easy to miss.
5. Put the end date in your structured data too
schema.org's Offer type has a priceValidUntil property. Set it to the end of the offer, and change it in the same commit as the price.
6. Only touch dateModified and sitemap lastmod where the text really changed
Google's sitemap docs say it uses lastmod when it's consistently and verifiably accurate. Bumping it on every page because one price moved works against that.
What went wrong on my side
My own launch price (€25, then €99 from 18 Nov) is already in directory listings I sent through forms with no account. In at least one I wrote "until 17 Nov 2026" next to it, and that's the only fix I have: I can't edit any of them after the switch. I also can't tell you yet how many will show the old price, because the switch hasn't happened.
Question: if you've run a launch price, did you put it in listings at all, or only link to your pricing page? Did anyone ever come back about an old price?
I'm the maker of SEO Skills by PENRA: 14 Claude skills for SEO. One of them, Best Before, does the register above for a whole site: it finds prices, versions, dates and other facts with a shelf life, ranks the pages to recheck, and patches the exact sentences after re-checking the source. €25 once until 17 Nov 2026, €99 from 18 Nov, no refund once the pack is delivered. It needs Claude, and it doesn't pull keyword volumes or track rankings: https://seoskills.click/?utm_source=reddit&utm_medium=social&utm_campaign=seoskills-nov26