First up I will say: and everyone else
Now looking at your Big Gig.
You seem to make the GUI layouts for Apps but not the App itself. Now I know what that is and why that is important BUT most people around here (and everywhere else really) will probably not know the difference so will just expect that for $15 they will get a whole app that is essentially eBay. Done.
You are looking for people smart/experienced enough to know that coders are often the very last people who should be designing GUIs for the programs they make. As above I am assuming those people are a bit rare. Possibly total unicorns on Fiverr (at least the general site).
Dealing with Coders is also flawed as most are too arrogant to know they aren’t DaVinci and would be doing a better job with a real UX person in their pocket. Also they are selling the illusion of eBay for $15 so they aren’t parting with 42 cents for anything - even if it might let them play with the big boys at big boy pricing.
Maybe you need to sell a different service or work out how to draw in the 0.001% of people who a) know what you do and why and b) are knowing why they should pay when the others say they will make the whole app for 1/10th the cost (even if we all know it will be a basket case).