Seems that possibly Nigerian students based on feedback on this forum may need to put more effort into justifying coming to Canada but does not necessarily mean more get rejected than some other countries.
See this link to change
https://www.canada.ca/en/immigration-refugees-citizenship/services/study-canada/change-schools.html
For a masters although I do not know would think very unlikely in that price range. Expect there are some institutions that are cheaper than others but whether they are that cheap seems doubtful given international students if nothing else are seen as a profitable revenue stream
