In my experience, market size depends on the guys you draft. If you draft a bunch of guys with big contracts ie. Cano, Cabrera, Kershaw...your market size will go up.
I've done fictonal leagues with inaugural drafts before, using a team with "Average" or an "Above average" market and after the draft, the market size moved to "small."
If you draft a ton of young guys, which you might have done, your market size will be small because they will be playing with salaries at the league minimum because they aren't arbitration-eligible yet.
Just speaking from experience. Hope this helps.
