The salaries don't get adjusted until last-ish in the off-season processing.
the 49k salary on the guy was his salary before all of last season's trainings and pops he received.
If his stats seem to be truly amazing at his price, and you're buying around this time, its because someone is trying to unload him, before they can't afford them.
Similarly with older players... the salaries can go down because they are already dropping in stats. Its a risk you take either way, and just something to keep in mind at times of year when you buy on the TL.
the Salary..... don't rely on Salary when looking on TL. Focus on their actual skill levels, that will give you more of an idea of what their salary *should* be.
Zacharia Belkhaouas (17989884)
When I sold him his salary was 6026. But where his skills were.... he was clearly not a 6k player, guy who bought him knew it, or I'm assuming he wouldn't have wanted the guy so bad.