Customs Taxes on Items Brought into Bolivia Through the Airport?

by Larry
(Birmingham, Alabama, USA)

I am traveling to Bolivia soon. A friend of a friend asked me to take a few items to a relative living in Santa Cruz. When the package arrived, there were about 18 blouses, a few pieces of costume jewelry, etc. There was not ONE receipt. A person I know in Bolivia went to the customs office to ask what is done if there is no receipt. Again and again they repeated, there must be a receipt. Here are my questions:

1. Am I correct to assume that they will come up with a value and charge accordingly.
2. What is the percentage of value that is charged for clothing and toys?
3. If the tax on the items without receipts is too high, can I abandon the property at customs, or am I forced to pay the tax to enter the country. This is what will determine if I am going to even attempt to take the clothing in. I can't afford to pay hundreds of dollars.