A price of 4000 yuan for a Boston Terrier is not considered expensive; it's within the normal range. If the dog is purebred and of excellent quality, the price could be even higher.

Purebred vs. Non-Purebred Boston Terriers
It's quite challenging to find truly purebred Boston Terriers in mainland China. Many dogs claimed to be purebred might not be, and it's important to verify their lineage by examining the parents. Often, the Boston Terriers that people purchase are not purebred. So, what is the price of a non-purebred Boston Terrier? Generally, non-purebred Boston Terriers range from 1500 to 2000 yuan, and the specific price will depend on the puppy's overall quality and appearance. Additionally, Boston Terriers are often mistaken for French Bulldogs, but Boston Terriers generally command a higher price.
Boston Terrier Size Standards
Boston Terriers are categorized by weight as follows: under 15 pounds, between 15 and 20 pounds, and over 20 pounds but not exceeding 25 pounds. The length of their legs is proportional to the length of their body, giving them a distinct square-like appearance.
Key Physical Characteristics
Their head is square-shaped with a flat top, no wrinkles, flat cheeks, pronounced eyebrows, and a clear stop. The ideal expression of a Boston Terrier is alert and kind, showcasing their high intelligence. This is one of the breed's most important characteristics. Their eyes are set wide apart, large, round, and dark in color. The eyes are positioned at right angles to the head, and when viewed from the front, the outer corners of the eyes fall on the cheek line. Blue eyes or eyes with blue traces are considered a fault. Boston Terrier ears are small, either naturally occurring or cropped, and are shaped to match the head and positioned as close to the corners of the head as possible.