Build-A-Bestie was a store in Portland where girls build dolls called "Besties". It appeared in Crash Lands. Amanda, Cleo, and Jasmine took Wyatt here for his 12th birthday despite Mel telling the girls to take Wyatt to a place he would like. Wyatt becomes enraged and decides he wants a brother and names him "Crash" Wyatt and the girls return home and Crash comes to life as the brother Wyatt always wanted. It was not seen again until Mr. Poulos let Crash go and destroy it with Wyatt. The Employee from earlier comes and "destroys the place like it destroyed his manhood".
A shop owned by Build-A-Bestie to fix broken dolls also appears in Crashus Maximus where Wyatt takes Crash to get fixed after he gets struck by lightning. The Employee from before owns this shop
.It´s possible that build a bestie is a chain since the store was destroyed but there are still other build a bestie buildings like build a bestie warehouse.