BDC Consulting analysts have calculated how much you can earn with an IDO on Polkastarter — and it's a lot... as long as you buy in at the right moment (see the chart):
Buy tokens during the IDO and sell right after the listing: the average return is x23 (min 67% with eMoney Public and max 9191% with Polkamon);
Buy in at the IDO and hold for a short while after the listing: x27 on average (min 146% among the projects we've studied and max 11060% with SuperFarm);
Buy after the listing: the average return is 'just' 36%.
But the most interesting part is that the average returns keep growing, which means that the market is hugely undervalued.