Bits and bytes take up very little space. This site is mostly just text after all. So, no, they really wouldn't save much server space...though of course they would save some space, just not very measurable amounts.
Sent from my iPad
Technically, text is the most expensive data type in terms of space consumption. A typical 255-character field consumes 64 bytes. And storing a 3 character string in that field takes the full 64 bytes. In comparison, a double precision field can represent numbers up to 1.7*10^308 within 8 bytes.
That said, 52 records against the thousands of forum records (all text) isn't even a microscopic dent in storage requirements.
I would argue to take the old posts down as a matter of currency of information, as "Last minute rentals wanted" don't provide much useful research material. I suppose some renters might want to peruse through and see where demand might lie in the future?
Edit: there is also a data type for storing OLE objects like images, etc., in MS Access that is more expensive than text. SQL Server etc. store those objects as binary.
