What happen here if everything you said is to go by is that sometimes the margin between buying and selling is always high for example you might buy some coins for say $4800 and when you want to sell on that same platform could be $4730 which means there is a $70 margin loss there if you want to sell couple with another reduction you will face because of the implicit fee.
So, the small increment in the price of altcoins is not enough to cover for the margin described above and the fee attached to eventually give a profit and you have to either wait more for the Altcoin to appreciate more or btc to go lower.
There is no certainty that its going to turn profit on bittrex because even though the margin on buying and selling might be lower, the implicit fee might be higher than where you are currently trading. You are actually making profit but not enough to cover those costs.
This margin as you describe it is commonly known as "spread"
OP, did you make a market order or a limit order?
Market orders execute instantly, at the premium of you paying the spread. Limit orders become part of the order book, are not guarantueed execute, but are cheaper in that your counterparty (ie. the buyer / seller that makes a market order) pays the spread.
I assume you made a market order, as that's usually the default price your are offered when entering a sell or buy order, which could account for the price difference you are seeing.
So what is the proper way to make profit from such speculations? Wait when alts which I bought will rise in price more? Or how?
Yes, and that's the tricky part