JSON Parse Error

public with sharing class bugTest
{
    @isTest
    public static void TestBug()
    {
            Account TestAccount = new Account(name='My Test Account', Tax_ID__c='99-9999999');
            insert TestAccount;

            RecordType HouseholdRecordType = [select id from RecordType where name = 'Household Record Type' and SobjectType='contact' LIMIT 1];
            date birthdate = date.parse('03/21/1988');
            Contact TestContact = new Contact(Firstname='Frank',
                                                Lastname='Jones',
                                                AccountID=TestAccount.id,
                                                email = 'none@none.com',
                                                of_PSA__c=0,
                                                status__c = 'Active',
                                                of_No_shows__c =0,
                                                of_Cancellations__c =0,
                                                of_Disqualified__c =0,
                                                of_Participations__c =0,
                                                PIN_Plain_Text__C = '12345',
                                                MailingCity='coon rapids',
                                                MailingCountry = 'us',
                                                MailingState='MN',
                                                MailingStreet='432423 nowhere street',
                                                MailingPostalCode='45543',
                                                phone = '7625324246',
                                                gender__c = 'male',
                                                birthdate = birthdate,
                                                RecordTypeID = HouseholdRecordType.id);
            DateTime dT = System.now();
            date closeDate = Date.newInstance(dT.year(),dT.month(),dT.day());

            Opportunity TestOpportunity = new Opportunity(Name = 'Test Bid',
                                                    Major_Revision__c = '1',
                                                    Minor_Revision__c = '1',
                                                    StageName = 'Calendar',
                                                    CloseDate = closeDate,
                                                    TimeForce_Job__c = 'FPI-TEST',
                                                    Project_Manager__c = TestContact.id,
                                                    Test_Kit_Return_Order_Created__c = FALSE,
                                                    Test_Kit_Return_Order__c = TRUE,
                                                    COST_ACCOUNT_MANAGERS__C = 0.0,
                                                    COST_ADMINISTRATION_FINANCE__C = 91.74,
                                                    COST_ADMINISTRATION_INFORMATION_TECHNO__C = 0.0,
                                                    COST_RECRUITING_CALLERS__C = 0.0,
                                                    COST_RECRUITING_COORDINATORS__C = 25.35,
                                                    COST_SALES__C = 274.63,
                                                    COST_OPERATIONS_OFFICE__C = 86.63,
                                                    COSTOPERATIONS_SITE__C = 0.0,
                                                    COST_FIELD_MANAGERS__C = 0.0,
                                                    COST_DATA_MANAGERS__C = 0.0,
                                                    COST_RELATIONSHIP_MANAGERS__C = 5916.3099999999995);
            insert TestOpportunity;

            string costDataJson = '[{"COST_ACCOUNT_MANAGERS__C":0.0,"COST_ADMINISTRATION_FINANCE__C":91.74,"COST_ADMINISTRATION_INFORMATION_TECHNO__C":0.0,"COST_RECRUITING_CALLERS__C":0.0,"COST_RECRUITING_COORDINATORS__C":25.35,"COST_SALES__C":274.63,"COST_OPERATIONS_OFFICE__C":86.63,"COSTOPERATIONS_SITE__C":0.0,"COST_FIELD_MANAGERS__C":0.0,"ID":"'+TestOpportunity.id+'","COST_DATA_MANAGERS__C":0.0,"COST_RELATIONSHIP_MANAGERS__C":5916.3099999999995,"TIMEFORCE_JOB__C":"00828-GMIT"}]';

            List<Opportunity> costData = (List<Opportunity>) System.JSON.deserialize(costDataJson, List<Opportunity>.class);

            system.debug(costData);

            update costData;

    }
}