Gildea & Walker produced china in Stoke-on-Trent England from 1881 - 1885. Their name changed through the years as the company changed ownership. Some books that may be informative is "Stoke-on-Trent A History" by David Taylor and "Stoke-on-Trent a Journey Through the Potteries" by Steve Ainsworth and Tony Lax. These are about the area known for pottery production.
I have seen the vibrantly colored and the brown and white china similarly priced with only a few dollars in difference. The value is in the piece. There were more plates and bowls produced than soup tureens. A tureen, sugar bowl, teapot, or anything with a lid and handles are more valuable than a plate or bowl. Also, lids and handles can easily break so that effects rarity and can increase value.
I saw a set of three Gildea & Walker bowls that sold for four dollars on an estate sale page and the same three appearing on eBay for much much more.