The prices for Ashgate publications is outrageous, imo. However,
copies can be obtained on the secondary market (review copies, used
copies) at substantial reductions.
Bookfinder or AddAll turn up some bargains.
There is also a remainder website in the UK (don't remember the
name at this moment) which sells older publications at a fraction
of list price. Someone, please provide the website!
Good luck! Thomas.