What Qualities Should I Look While Purchasing A Havanese Puppy For Sale?

While you are purchasing a havanese puppy these things should be taken into the account
There must not be complete absence of black (or chocolate in the chocolate dog) pigmentation on the eye rims, nose or lips as it's a disqualification point for havanese breed in competition
There must not b any Coarse, wiry coat.
There must not be any spot on the legs of havanese puppies( means that legs must be of only one color)

However while purchasing an adult havanese puppy (whose age is more than 12 months) two more things should be taken into account
Its height must be 8-11 inches. More or less height is not considered as normal
There must not be an atypical short coat on an adult. (Atypical refers to a smooth, flat coat with, or without furnishings.)

The proper vaccination of the puppy should be done as havanese puppy is double coated and if there is no vaccination, the worms develop in the coat of the havanese breed. Ask the seller about the vaccination of the havanese puppy.
One more thing should be noted that there is no preference of one color on other or multi color of havanese. So no extra payment should be paid while buying a havanese puppy due to its color.

I'm not sure which standard the previous answer refers to but the AKC standard is very different from that answer.  All of those things matter most to those who show their dogs like I do.  Also, I've been active in the Havanese breed for more than 8 years and have never heard of worms in the coat of any Havanese.  Even if that were accurate, vaccination does not protect against worms.