off the cuff guarantees formula

(prize pool)/(no. of winners)/(buyin+fee) gives you a set of odds

(those odds)*(no. of winners) gives you max worthwhile entrants

For example: If the guarantee is $400 and 5 win and the buyin+fee are $5.50 the odds are about 14.5:1. If you multiply 5 by 14.5 you get 72.5, so as long as there are 71 or fewer entrants it's worth your while to enter the guaranteed tourney. Once the number of entrants including yourself is 73 or higher, the potential for profit is reduced so much that it ain't worth it.

Makes sense?

umm...no.
basically you are saying "if i am paying more than 1/n of the prize fund, where n is the number of participants, i don't want to play" or in simple words, "i hate rake"
well - stick to freerolls, then. and good luck.

The primary source of profit in playing poker tournaments should be that you have better skills than your opponents. Hopefully so much better skills that it more than compensates for the rake.

When the guarantee adds an overlay, that's additional profit, but it will mostly be marginal. Besides, if you get rakeback, your share of the overlay will usually be deduced from your MGR, so you will actually be paying part of it anyway.

What bugs me is that the entry fee makes entering MTTs the same kind of losing proposition that buying lottery tickets is. You know the old saw: If the cost of the lottery ticket is $2 and you have a 1 in 20 million chance to win the grand prize, then the grand prize must be at least $40 million to make buying the ticket financially sensible; but lotteries are structured so that either the grand prize is $38 million or it's $40 million but your ticket sells as 2 lines of numbers for $5. So lotteries are sucker gambling. Well, because of the entry fee, entering MTTs turns into the same kind of sucker gambling, the only difference being that in poker skill makes a difference and in lotteries it doesn't. By simple logic only people who are of superior skill level would bother to enter MTTs if they knew what they were doing; which would reduce their relative skill level within the tourney and still make bunches of them into losing players. Something's wrong with this picture. Are we all getting ripped off by the MTT administrators?

Aside from the numbers, the real question is

" If I have had three glasses of wine, should I stick with the play money games"....

Humans have the tendency to think that we are better than we really are. Furthermore, we tend to attribute our wins to skills while losses are thought of as unlucky.

Then there are many players that are just down right suckers, but hope that they would catch the winning numbers or the lucky streak of cards to win the tournament.

Also there are players that play for the fun of it and really don't care reloading as long as they are having fun.

LOL. In all seriousness though, I have an answer for this. No. Don't stick with the play money games. Deposit a bunch of cash and let me know where and when you are playing...