I have found Etsy to be best when you need to import fabric from the U.S. Fabric is so much cheaper that even with the £15 shipping cost it costs the same as buying the fat quarter bundle/jelly roll here.
Fat quarter bundle
https://www.etsy.com/uk/listing/227906772
Jelly roll (£32 incl shipping)
https://www.etsy.com/uk/listing/227906860
Don't forget you may have to pay 20% VAT and Royal Mail handling charge on anything over £15 but most of my stuff comes through without it. If I love the fabric it's worth it.