Hi Laurie,
There are plenty of high hour ATPL and fATPL instructors around at the moment all waiting for the job market to open up. When this happens the demand for instructors is likely to increase.
I dont think the £5k to get a FI rating puts many people off but the requirements to maintain the rating puts off airline pilots who wish to instruct in there spare time.
We have recently seen jobs advertised on this forum so they cant be that hard to get if you are prepared to look around.
cheers
MJR