Global Travel out of LAS will give you 20% to 25% off any TWA ticket (except St Louis). Most Travel agents have access to this discount through Global. TWA (through a bulk fare outlet) has 3 day advance purchase seats from select city pairs that are much cheaper than the 21 day advance fares.
When TWA brought back its ownership from Ican(sp), [who had run the company into the ground] they had to give him $5000,000 of discounted TWA tickets (priced at 40% off) spread out over a 10 year period. He turned this over to Global who markets the discounts at 20% off and they pocket the differnce.