I want an ac, but getting one installed is so ridiculously expensive.
I had a split ac unit installed about 5 years ago and it cost me like 1300€. What are they charging for it where you live then?
Might be a regional thing. Here in Australia our houses often have sliding windows, so it’s not hard to open one and mount an aircon in the space, sealing around thy edges.
I think some other countries use hinged windows which are less amenable to being violated by a Window Rattler. Placing the entire unit inside against the window and creating some improvised ducting for the outdoor air inlet side can also work in a pinch.