They're usually hard to get because bootlegs are illegal. But if you're
lucky, you can run into some at a record store. They're generally easier
to buy in Europe than the States.

Another way is to buy bootlegs is via mail-orders. Mail order companies
that carry Marillion and Fish boots are located in Germany and Italy, but
this changes often. Check specialized magazine's for ads, otherwise ask on
the list if anyone has more info. Sometimes bootlegs are even offered for
sale on the list.

The Marillion and Fish fanclubs also offer several 'official' bootlegs for
sale, more on this in question 6.2.