i’m not sure how much this cost me as there were popups all over the screen. is there a way to cancel the download if i find that i inadvertently spent too much for it?
There is NO obligation to pay anything. You are asked to donate to the project while the download is carried out.
Conversely, stopping the download will not stop any donation or allow for a refund.
If the Download page is confusing you can download from a trusted download site, such as FileHippo or Softpedia
In any case, LibreOffice is ALWAYS free to download and use.