Your arithmetic on the strict rule is right. Maximum offer equals 0.70 times ARV, minus repairs, so 227,500 minus 35,000 gives 192,500. The loose usage you'll see on forums drops the repair subtraction and treats 70 percent of ARV as the purchase ceiling on its own, which produces 227,500 and a much thinner deal wearing the same label. Same words, very different number.
What the 30 percent is actually buying you: on a 325,000 resale, selling costs at 7 to 8 percent are roughly 23,000 to 26,000, buy-side closing and title maybe 4,000, and five months of carry on a short-term loan plus taxes, insurance and utilities lands somewhere around 10,000 to 14,000 depending on rate and points. Add the 35,000 of work and you've consumed most of the spread at 192,500. At a 240,000 purchase the same house is a break-even exercise unless the repair number is really 20,000, or the true ARV is 350,000 and you're pricing off stale comps.
The part I'd question first is the 240,000 itself. Unless you're watching deeds directly you may be reading owner-occupant purchases as investor buys, and roughly a dozen states don't make sale prices public at all, so "what flippers paid here" can be a guess dressed up as data. Confirm what those buyers actually were before you conclude the market has repriced.
Operators who've dropped the rule generally replace the percentage with a dollar floor, something like a minimum projected net after all costs at a resale price 5 percent below their ARV, and a hard limit on days from close to list. The percentage is a screening shortcut. It stops working exactly where you found it, so at 240,000 you'd need the full cost stack written out before you'd know whether anyone is making money.