For Chinese stamps, proper lotting is extremely critical, as is the need for expertizing. The first factor is pretty much beyond your control; the second isn't, other than the fact that in the minds of international buyers, you may select the "wrong" expertizer. Also, if a $50-60 purchase is within your comfort zone (before you begin), buy a 2012 (NOT 2011) Gibbons Part 17 Catalog, which covers China, Macau, Hong Kong, etc.
Myself, I would not dump a Chinese collection into the eager hands of an auction house. I'd prefer to deal with Michael Rogers or Rising Sun, etc., directly across the table, which in some cases, would eliminate the need for expensive expertizing.
OP, are you an experienced seller on
ebay? That would affect the rest of my answer.