For simplicity’s sake, we assume that we apply market taking to all of the following situations.
So if we want to buy 1337 with BTC, we'll have to pay 4 sats.
If we want to buy it with Doge, we have to pay 0.06288547 x 0.00000065 = 4.087 sats.
If now, we want to sell it on the BTC market, we will sell it at the price of 3 sats.
And if we want to sell it on the Doge market, we'll get 0.06000002 x 0.00000064 = 3.84 sats.
So, for that coin and at the given moment, if we want to buy it we should do it on the BTC market, and if we want to sell it we should do it on the Doge market.