What's the cost to restiore an Honda XR / XLR

Why does an XR / XLR restored from a pro cost 5 to 6,000 €?
- purchase            1000/1500 €
- labor 50 / 75hx35 € = 2200 €
- spare parts               = 1500 €
-VAT 20%                    = 850 €
- guaranteed hidden defect for 2 years =?

To explain that Classic Red just pays its costs and can only function because the one who manages the purchases/sales do it passionately without remuneration.
XR600 HONDA 1987 CLASSIC RED RESTAURATION-2.jpg