I do think you have a sound idea imo..from past dealings with franchises, something always seems to be supplied as an ongoing expense, normally stationery........If the site would cost many £kkk's to build, then selling the "pattern" with no ties, and with no ongoing monthly fee paid to yourselves, I would suggest £500 -£1000 far too cheap in the first place.....why not find a reliable friend in a different area to you, and set up a trial area with your pattern....see how that runs and then use as your selling example......I wish you luck, and hey, just giving you another angle..........no expert here.