About the Final Destination example. Student accommodation is actually a lot better these days and students can live in very nice places, provided they know where to look or they know someone etc. I lived in a very nice student house for three years at a reasonable rent price. Laurie and Nick could feasibly live there if their parents were paying their rent. Some parents also open up savings bonds for their kids to use when they turn eighteen.
Clean up the trope?
It seems to me one of the big issues here is too many 'but they live in this area so it's ok' I think we should consider trimming or reorganzing the trope, so that large places in say NYC or fancy neighborhoods are left, but ones where the location makes it reasonable for space are removed or put in an averted section.
For instance, Friends is clearly an example, set in Manhattan with a large apartment. The Big Bang Theory is not, as it's a meh part of LA where rent is a fraction of NYC due to far more space. Or the drew carey show, since it's a meh house in the midwest.
The CBC program "Undercurrents" actually did a story about this in 1998: http://archives.cbc.ca/arts_entertainment/media/topics/3624-16046/
(starts at 14:53). If this were TOW I would add it to a list of references, but I don't know where such a link might go in a TV Tropes article...
Regarding apartments, I recall at least two shows—MTM and Dear John, both of which series began with the title character living in a one-room apartment, albeit in the case of MTM the set designers tried their best to make it "cute". Then after a few seasons, we found both MTM and Dear John in spacious highrise units, without any apparent advancement in their workplace responsibilities, duties, status or salary. (I wonder how many highrise apartment blocks Minneapolis had in the early 1970s.)
Was this a "thing"? Has anyone else noticed it, or have I missed or forgotten something about these shows?