Can you easily generate the money for each level to get the books?
No, it's not easy. It is, however, possible.
Here is my understanding of how buying/selling works. The numbers are not exact. List value = value listed on the item while glancing at it in your inventory.
Selling stuff40% of base value as a base
10% increase per point of Bartering
0.5% increase per 5 points point of Attitude (which can be negative for a decrease)
5 Bartering + 100 Attitude (max) = Sell stuff at list value
Buying stuff250% of base value as base
20% decrease per point of Bartering
2.5% decrease per 5 points of Attitude (again, can be negative)
5 Bartering + 100 Attitude = Buy stuff at list value
Attitude is based on previous interactions with the character, your Charisma (5 per point), and your Reputation (also 5 per point). There are also Talents which reduce Attitude, so do not have your Know-it-all dealing with merchants.
As you can see, Bartering is huge. The best bet is to have a character who is skilled in both Bartering and Charisma, since the abilities synergize very well.
