re-posting manual trans question 93 325i

No replys last time thought I'd try again. Thanks for looking.
Chris

My sons '93 325i has recently started making a clicking noise coming from
the shifter mainly in gears 1,3 and 5. It's kind of a ticking that increases
if you get 'on it' and it also increases in frequency as the revs increase.
Sounds kind of 'metal to metal'. Doesn't sound real bad but isn't good,
that's for sure.

Car has about 80k miles. We've owned it for just over a year and the p. o.
seemed to be pretty fanatical about maintainence.

Low fluid? Old fluid? is there any other likely culprits?

TIA,
Chris