Surplus on revaluation (Pricewell)

sir, I present you the whole question but it is enough for us to look at the 1st note here

The following trial balance relates to Pricewell at 31 March 20X9:
$000 $000
Leasehold property – at valuation 31 March 20X8 (note (1)) 25,200
Plant and equipment (owned) – at cost (note (1)) 46,800
Right?of?use assets – at cost (note (1)) 20,000
Accumulated depreciation at 31 March 20X8:
Owned plant and equipment

12,800
Right?of?use plant 5,000
Lease payment (paid on 31 March 20X9) (note (1)) 6,000
Lease liability at 1 April 20X8 (note (1)) 15,600
Contract with customer (note (2)) 14,300
Inventory at 31 March 20X9 28,200
Trade receivables 33,100
Bank 5,500
Trade payables 33,400
Revenue (note (3)) 310,000
Cost of sales (note (3)) 234,500
Distribution costs 19,500
Administrative expenses 27,500
Equity dividend paid 8,000
Equity shares of 50 cents each 40,000
Retained earnings at 31 March 20X8 44,100
Current tax (note (4)) 700
Deferred tax (note (4)) 8,400

Total: 469,300 469,300

(1) Non?current assets:
The 15?year leasehold property was acquired on 1 April 20X7 at a cost of $30 million.
The accounting policy is to revalue the property at fair value at each year end. The
valuation in the trial balance of $25.2 million as at 31 March 20X8 led to an impairment
charge of $2.8 million which was reported in the statement of profit or loss and other
comprehensive income in the year ended 31 March 20X8. At 31 March 20X9 the
property was valued at $24.9 million.
Owned plant is depreciated at 25% per annum using the reducing balance method.
The right?of?use plant was acquired on 1 April 20X7. The rentals are $6 million per
annum for four years payable in arrears on 31 March each year. The interest rate
implicit in the lease is 8% per annum. Right?of?use plant is depreciated over the lease
period.
No depreciation has yet been charged on any non?current assets for the year ended
31 March 20X9. All depreciation is charged to cost of sales.

(2) On 1 October 20X8 Pricewell entered into a contract to construct a bridge over a river.
The performance obligation will be satisfied over time. The agreed price of the bridge
is $50 million and construction was expected to be completed on 30 September 20Y0.
The $14.3 million in the trial balance is:
$000
Materials, labour and overheads 12,000
Specialist plant acquired 1 October 20X8 8,000
Payment from customer (5,700)
––––––
14,300
––––––
The sales value of the work done at 31 March 20X9 has been agreed at $22 million and
the estimated cost to complete (excluding plant depreciation) is $10 million. The
specialist plant will have no residual value at the end of the contract and should be
depreciated on a monthly basis. Pricewell recognises progress towards satisfaction of
the performance obligation on the outputs basis as determined by the agreed work to
date compared to the total contract price.
(3) Pricewell’s revenue includes $8 million for goods it sold acting as an agent for Trilby.
Pricewell earned a commission of 20% on these sales and remitted the difference of
$6.4 million (included in cost of sales) to Trilby.
(4) The directors have estimated the provision for income tax for the year ended 31 March
20X9 at $4.5 million. The required deferred tax provision at 31 March 20X9 is $5.6
million. All adjustments to deferred tax should be taken to the statement of profit or
loss. The balance of current tax in the trial balance representsthe under/over provision
of the income tax liability for the year ended 31 March 20X8.

Based on this info the book calculated cogs like this:
Cost of sales $000
Per question 234,500
Contract (W1) 14,000
Agency cost of sales (W2) (6,400)
Depreciation (W4) – leasehold property 1,800
– owned plant 8,500
– right?of?use asset (20,000 × 25%) 5,000
Surplus on revaluation of leasehold property (W4) (1,500)
–––––––
255,900

MY QUESTION: I AM ALSO CALCULATE LIKE THIS BUUTT EXCEPTION is RS AMOUNT. I don’t get it why surplus amount include in cogs, i never seen before. please clarify in simple way to me. Please explain me simple way