Welcome to the GF! Nice looking boy you have there. His vent area does look raw. Of age male Leopard geckos will drag their preanal pore area to mark their territory for breeding. The waxy substance on the preanal pores will rub off and mark the areas. The look funny while doing this...
Great, please post what they did to make it right so others can see. I've never used Rainbow Mealworms before but I've never heard any negative on them before, only positive.
You posted in the right section, you just need to change the prefix from WANTED to FOR SALE.
(I moved it to the wanted part of the leopard gecko classifieds. Hope that's ok.)