Agree with Swee'pea99 that there are plenty of bikes on ebay that do include postage. And there are some real bargains to be had.
The main thing you need to be careful about is making sure you get the sizing right. Some sellers have only a vague notion of what size their bike is, and you will see people quoting sizes in both inches and centimetres. In any case, as you will find if you search through some of the older threads, bike sizing seems to be more or an art than a science with different manufacturers using different ways of measuring their frames.
Given this, you should email the seller and ask how tall they are and how well the bike fits them. Most will give a sensible response.
The main thing you need to be careful about is making sure you get the sizing right. Some sellers have only a vague notion of what size their bike is, and you will see people quoting sizes in both inches and centimetres. In any case, as you will find if you search through some of the older threads, bike sizing seems to be more or an art than a science with different manufacturers using different ways of measuring their frames.
Given this, you should email the seller and ask how tall they are and how well the bike fits them. Most will give a sensible response.