If you worked out the 25%, 50% and 75% quantiles for the amounts bet, you'd have 3 lines representing equal number of four equal groups of amounts bet. Might provide some insight, might not be worth it if it's a hassle.
Sounds interesting, but confused.
If I understand you, I'd have lines for (0-25%, 25-50%, 50-75%, 75-100%, and total) - that's 5 lines. Is that what you mean?