Standard BRM rules aside (ex: 100 bi's for level), It's not always bad to start with a low amount. $50 can be a good start. Remember that you are going to have some horrendous downswings in mttt, but if you are a competent player the lower levels (.27c, .55c, even up to 2.50) can be profitable if you choose your game wisely.
First off, turbo, or hypers are pretty much a no-no. They're a crapshoot at the lowest levels. Lots of flipping in multiway pots. Sure, these games usually have great guarantees and huge fields, but if you're grinding up your 'roll, they are a killer. Too much variance.
Cap and non-guarantee regular speed (10 min levels) are a better bet. Smaller fields (which also means less players paid, but generally easier to attain due to less flipping due to deeper stacks) and a slower pace of play means more time to learn player habits and exploit any edge you may have, or at the very least wait for a good spot to have a go instead of getting blinded out and desperate. The downside is that since these games have no guarantee, the payout per spot tends to be slightly lower. Some small Cap tourneys on PokerStars for instance actually pay out less than your initial buy-in for a min-cash. But we're not going for mincash, now are we? . They also take longer to fill on some cardrooms, and if they are running at the same time as a GTD game, they will usually (but not always) have more regs playing.
1) Avoid turbo or hypers like the plague
2) GTD tourneys are great, provided they are played at peak traffic times and are not T or HT
3) Cap and deepstack games that are not running against large GTD games are juicy, but check the pay structure. Less mines to step on, but lower payouts for the effort.
Also, even if one is using good brm and playing well, don't be discouraged if you go broke in mtt. It happens to the best of us. They can be a great br boost if you score deep, but for every deep run, expect hundreds of busts and mincashes.