The best place to buy from is your local independent bookshop, as this also supports these shops. Below are some links you can use to buy Mr Shaha’s Marvellous Machines if you don’t live near a bookshop.

Amazon

Bookshop.org (supports independent bookshops)

Blackwells

Foyles

Hive (supports independent bookshops)

Waterstones

If you’re outside the UK or Australia / New Zealand, the best place to buy from if you want to save on postage costs is Book Depository