Any performance guaranty issued pursuant to this section shall be equal to an amount not to exceed 120% of the cost of installation, which cost shall be determined by the Municipal Engineer according to the method of calculation set forth at N.J.S.A. 40:55D-53.4 for improvements which the approving authority may deem necessary or appropriate, including streets, grading, pavement, gutters, curbs, sidewalks, streetlighting, shade trees, surveyor's monuments, as shown on the final map and required by the Map Filing Law, N.J.S.A. 46:23-9.9 et seq., water mains, culverts, storm sewers, sanitary sewers or other means of sewage disposal, drainage structures, erosion control and sedimentation control devices, public improvements of open space and, in the case of site plans only, other on-site improvements and landscaping. The Municipal Engineer shall prepare an itemized cost estimate of the improvements covered by the performance guaranty, which itemized cost estimate shall be appended to each performance guaranty posted by the obligor.