Canon 20D advice

My 20D shutter button has begun to need increasing amounts of pressure to
release the shutter.
The shutter button on the grip remains fine as does shutter release on the
remote release, it would appear that only the button on the camera is
getting a bit tired!
I've had the camera just over two years and must have taken a few tens of
thousands of pictures.
I have just spoken to a Canon repair centre (in UK) who want 100gbp, plus
tax to "have a look". Prior to packing it up and sending it off I though it
may be an idea to see if anyone on this group had experienced a similar
problem and did they solve it for a few pence......?
Should I just squirt the button with a drop of WD40, or not? (Not entirely
serious!!!!)
Thanks for any help
Cheers
DP