50 glass bottles from suppliers can run you from $35-60. 99% of the time, they are not clean or sanitized, so you'd also have to have them properly cleaned if you don't have a bottle washer at home. This is time and/or extra expense, and your time is money also.
FXRich is correct on the additional cost of labels, time to print them, and sitting on product while you're trying to sell it is also costly. 50 10ml bottles (of the same flavor/nic-strength) are hard to move, even for a retailer... trust me! Honestly, you'd be lucky to make $20, and more realistically breaking-even or having a loss!
Furthermore... selling a re-packaged product for profit is not really kosher (moral), and in some instances illegal if the product you're re-packaging is trademarked or licensed by the original manufacturer.... even if it is a house-brand from the local shop...