There's also the consideration that there are far more C-tier events out there than higher tier events, so unless you're flexible enough to travel to another state for a weekend tournament, a C-tier may simply be what's available.
For a graphic illustration of this, go to dgmapper.com and compare the view of C-tier events through the end of the year vs. the view of B-tier, A-tier, etc. events.
This year Charlotte has:
6 C-Tiers
3 B-Tiers
2 A-Tier
2 Majors
*(not including the statesville C-Tier)
Only the women's global tournament (C-Tier) is listed... I don't think DGMapper.com is a good resource.