Fees and Cost to me and you - the more you know!

pretend I'm selling a NWT Zara top that cost me $40.00. I lost my job and the unemployment office is backed up 12-16 weeks was on this my only source of income (true story) I have it listed and sent an offer to likers: Listing Price (after applying 20% OTL) $20.00 Poshmark Fees (20%) $4.00 Shipping Offer Discount $4.99 Revenue (after PM fees) $11.01 ‼️ Gross Profit ($) $-28.99 The buyer pays sales tax based on their state, in Florida and South Carolina it's 6% so let's say they live there. Price: $20 + 4.99 + $1.20 - so you pay 26.20⁉️ And I take home $11😭❗🤷‍♀️ Ideally, we develop trust and move to IG but for now I'm just sharing the way it works and why lowball offers really get to us - other deal posts I have made are showing all my socials, or Google me and my stuff comes up quick! just tell me what you liked here and we'll come up with it.