

Yup. A $100-200 window unit(personally I prefer “portable” units with the exhaust hose to the window - keeps the main unit out of the sun that causes it to work harder) will be your best bet every single time. But sure, go ahead and check the price of tinting every window(about $20 per window) or getting blackout curtains(~$20 per panel in my experience) or any of the myriad of lesser solutions. Then, when you’ve spent as much or more with worse results and finally cave on getting a small unit, you’ll wonder why you ever did anything else before. Nevermind the fact that OP basically said “so aside from all the normal passive options, what else is left?” AC. That’s what’s left. Unless you want to advise them to replace all the insulation/windows/seals in their house.
I mean, sure, if you want to look like you live in a meth lab. Or you could spend a little bit and have something 100x better and actually functional and not be miserable. This is like that whole boot problem: you can only afford $20 boots so you buy them and they wear out in 6 months. Over 5 years you spend $200 when a nice pair that would’ve lasted as long or longer would cost you $100.
You can get an ac for like $60 new, like $20 on Facebook. Walmart has Artic Kings on sale every year for that much. But yeah, spend hours of your time Macgyvering a makeshift solution that maybe drops you 10°. You know what “10° degrees cooler” is where I am? 100°. You’d still be plenty miserable.