Looking at it again, sometimes I see similiar shapes at household auctions. From the 1980s maybe when stores like JC Penny's and Pier I sold southwest themes or geometric designs in peach cream colors. Vases had no rims or small rims. This looks lots better than those and they sometimes go from $20 depending on size at auction.
We are going to have to assume a UK was importing same things at same time we saw them in 1980s. I think it is worth lots more than $20. Then again my expertise is zip in the vase department.