What? Yes. While the 50% offer is going on it is viable to sell those premium tanks that you can rebuy indefinitly.
I sold Tornvagn for 1.9 million credits.
I bought consumables for those credits, effectively saving 1.9 million credits.
If I buy back Tornvagn I will have to pay 2.5 million credits. (if, lol) That's a loss of 600k credits.
So I would effectively saved 1.3 million credits.
Just be careful to only sell tanks that you can buy back indefinitely. Premium tanks that are listet in the tech tree can only be reestablished within 3 days.
Do not sell all your premium tanks, you need some to farm credits to buy them back.
I had 27 tier 8 premiums but I am in constant lack of credits. I never play the Tornvagn or the Caliban because I consider them to be toxic and shitty tanks. I got them in the loot boxes. Since I never use them I might as well sell them as I can always rebuy them if I should develope the desperate need to play them and under these curre t circumstances I'd still have saved credits.
I hope this helps some people save credits.
Again, be careful which premium tanks you sell!
Also, this is a better option than selling decorations at the moment because decorations are also 50% off so you would not take advantage of the sale at all.
Source: https://www.reddit.com/r/WorldofTanks/comments/u0x9id/sell_your_premium_tanks/