Hi,
During early seasons of ESEA, they weren't offering the 4th place money for people, but flights were also significantly less expensive back then than they are now. If you were first or second place during the regular season, you might solidify a LAN position 6-8 weeks prior to the LAN. ESEA was pretty good about scheduling the LAN a good 4-5 weeks after the final playoffs match, so even teams seeded third or fourth generally knew at least a month ahead of time.
If your team had a sponsor, generally they would cover most or all of the flights once you solidified your LAN qualifier position. Unfortunately, most teams didn't have sponsors. If you had no sponsor, you were going to be in the negatives unless you took first place, and even then you'd barely be money ahead, if at all. Like alfa said, it was all about the experience and the prize pool was just a way to lessen the overall cost of your trip. If one of your teammates happened to be local to Dallas, they would probably pocket a bit of money from the prize pool.
Some teams had cocaine-addicted sponsors who generally went by the name blackfoger who booked hotel rooms for 12 people at a La Kwinta (if you know, you know) motel in Dallas for an entire LAN weekend using a stolen credit card, then stopped answering their phone, swearing up and down that they were stuck in airport security, then accidentally answering their phone once, and upon realizing who had called them, used a blatantly fake voice and accent to say, "oh sorry James isn't here, this is his roommate."
Players from both "blight gaming sponsored teams" were locked out of their hotel rooms on the second day, with hotel staff refusing to let anyone back in to get their things until another credit card was presented.
That was ESEA season 6, with a prize pool of something like $4200. First place received $2000 and last place was $400 I think. Two people to a room, roughly $90 per room per night brought hotel costs to $100ish per person for the weekend, plus flights which were generally $150-200 per person. Even the first place team would only end up putting around $50 in each player's pocket, and you'd likely spend at least that on food and drinks over the weekend.