I sold each of my 2 RX480's for over $100.00 more than what I purchased them for a little less than a year ago.
I figure with the shortage and high price I could sell them for more than I would mine with them in the next few months and I'll use the money to upgrade.
Haven't decided what tho.
Maybe with the money I'll buy THREE RX 580's when they are back in stock.
Or just go with a GTX 1080 Ti.........
I think about this every once in awhile too, but I re-did the math after reading this and decided that for me keeping them is the best deal right now. While it is true you can get $100 or more than you paid for them on ebay, in my case I am grossing $36/day on a 6x RX480 rig, so even after electrical costs I am clearing $34 which is about $5.50/day profit for each card.
So an average RX480 that I paid ~$200 for I could sell for $300 on eBay. To keep it simple let's be generous and assume the $300 is after all selling costs are subtracted, shipping, ebay fees, etc. Let's also just use $5.00 day for net income per card on average to account for daily fluctuation. After only 60 days I would make the same $300 as I would by selling but I would still have the cards. Even if mining falls off somewhat to only around $3.00/day profit, after a little over 3 months (100 days) I would still have the same profit as selling while also retaining the cards.
The cards will continue to hold value for sometime, so even if they dropped to $150 after the three months, I still netted $300 (mining) + $150 (net after selling) or $450 in total. Sure everything could collapse at any moment, but if you believe that is the case you would probably be better off just shorting the market.
So for me I would rather keep them for now and continue to mine. In 60 days I would have $300 and the cards would still be worth $200-$300. Since all my cards are ROI it simply comes down to which way I will make the most profit off of them.
Also, even if everything works out the way you think, who is to say the new cards released in a few months will not also be selling at a premium. So the way I look at it, I got a discount when I bought my cards (compared to what I could by them for today) and I am also continuing to make $5/day from each one, so for every 60 days that profitability keeps up, it's like doubling my investment (again and again).