Is Tian Yingzhang's calligraphy collectible?

That depends on whether it is a boutique or not. Tian teacher is a national player, especially regular script, which looks solemn. If it's a boutique, it's valuable. I have been studying his hard-pen running script recently. Compared with others, I feel that tian teacher's running script is really as he said: the momentum of running script should be elegant and solemn. He is indeed a calligrapher.