I think you're thinking of it a bit backwards.
Why limit your price to LTV for the offline-only version? Think of it as a full blooded product, instead of trying to squeeze it into the SaaS thinking model you've got already.
Plenty of enterprise (and such) clients wouldn't balk at all at a $500 fee. Brainstorm your target market and price accordingly. In other comments, you're mentioning the support burden - I don't think you should sell the offline version if you're not ready to lift that burden, and thus should price it in a way where this is attractive to you.
Offline versions are usually used by more demanding customers in the current day and age - the web is where you go for the user-friendly version.
I’m certainly open to charging more, but I operate in a price sensitive hobby market. If we do go for it, I’ll definitely try a higher price first. No harm in trying.
You can always try to categorize your target audience, and figure out their preferences.
The main thing to focus on here, however, is that this offering would not be for your usual audience. If that's all you expect from it, I would rather not bother. It's a separate market, and while there's some bleedover, I think you'll be surprised how different they are.
You can always try to play it safe and put in a contact form for discounted quotes (nonprofits, individuals, etc). This depends a lot on your capacities, but it could quickly tell you if you're pricing out desirable customers.