I think Melba's end game is about profit. I can't imagine how much she could have made on this, but I think she wants to position herself for the long haul as a go-to Bigfoot expert in order to collect appearance fees and the like. I don't know how much the TV shows pay, but I assume it's a decent check. I don't think she really believes she's proven a new species and never intended the paper to withstand rigorous scrutiny from real scientists anyway... just people who will accept pseudoscience and conspiracy theories as fact.
I imagine Dr. Meldrum supplements his income quite nicely with all the Bigfoot stuff he's into. Except Meldrum is a real scientist with credentials and would never be involved in a hoax, IMO. In fact, he is quick to point out the hoaxes, so I don't begrudge his taking a profit the "honest" way from this phenomenon which is admittedly very entertaining.
All of this is just my opinion, of course. Sykes will probably be the final word on Bigfoot for me, at least as a flesh and blood creature, so I'm just waiting on that.