Yes, you should think about how much you are worth, and aim for that pay. However, in hourly positions, you don't really have the option to negotiate. They may ask what type of pay you are looking for, but usually what you say doesn't matter because they already have a determined pay rate.
According to the latest estimates, the cost for taking the HESI exam can range anywhere from $35 to $70. Costs vary according to the institution administering the test and you should contact your chosen location for details on this.
If you are a donor volunteer, these tests are part of the registration process. You may have to pay for the testing, which ranges from $50 to $100. The test identifies your human leukocyte antigens (HLA). The results are input into the marrow registry and used to make a preliminary match with compatible recipients.