The quality of your pay depends on the value of the token you promote. I think they should rather pay in established cryptocurrencies. I strongly believe the exact pay promised to hunters in fiat value in the beginning (whether small or big) should be guaranteed & paid in the end of the promotion.
Well, It is heartbreaking to see hunters work so hard only to be given peanut. The developers are probably doing this because they raised inadequate funds or don't care too much about hunters. It's hard to raise funds these days... i won't be surprised if the latter is one of the main reasons paying adequately is difficult.

You should research into a project before joining. You need to be sure it's not scam or substandard project. Scams and substandard projects hardly raise enough fund thesedays. Solid projects are hard to find but they have higher chances of raising higher funds and paying their hunters