This code system http://hl7.org/fhir/price-component-type defines the following codes:

CodeDisplayDefinition
base base pricethe amount is the base price used for calculating the total price before applying surcharges, discount or taxes.
surcharge surchargethe amount is a surcharge applied on the base price.
deduction deductionthe amount is a deduction applied on the base price.
discount discountthe amount is a discount applied on the base price.
tax taxthe amount is the tax component of the total price.
informational informationalthe amount is of informational character, it has not been applied in the calculation of the total price.
<status value="draft"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="Codes indicating the kind of the price component."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/price-component-type"/><content value="complete"/><concept><code value="base"/><display value="base price"/><definition value="the amount is the base price used for calculating the total price before applying surcharges, discount or taxes."/></concept><concept><code value="surcharge"/><display value="surcharge"/><definition value="the amount is a surcharge applied on the base price."/></concept><concept><code value="deduction"/><display value="deduction"/><definition value="the amount is a deduction applied on the base price."/></concept><concept><code value="discount"/><display value="discount"/><definition value="the amount is a discount applied on the base price."/></concept><concept><code value="tax"/><display value="tax"/><definition value="the amount is the tax component of the total price."/></concept><concept><code value="informational"/><display value="informational"/><definition value="the amount is of informational character, it has not been applied in the calculation of the total price."/></concept></CodeSystem>