1. Skins are priced the highest on the Steam market, compared to any other 3rd party sites like csgoempire, csfloat, or buff163.
2. However, people tend not to sell on the Steam market due to the initial 15% fees, but mainly because it's hard to cash out the Steam balance.
3. There is a huge secret method not many people know of. Steam released the Steam Deck and you can purchase this with Steam balance.
4. The secret here is to make the most profit, you will buy the
'Certified Refurbished' Steam deck (linked here) sold by Valve that is like 25% discounted.
5. If you go on Facebook Marketplace, Kijiji, or Craigslist, you see people selling 'used' Steam decks for around the same price, or even more!
6. You should buy the refurbished one directly from Valve (check if it's in stock), and sell it on Marketplace for basically the same price you bought it for.
7. I have cross-checked with many other online sites and this method provides the most return for your skins, with just that 15% fee from the Marketplace!