Trade insurance is not £1000 a month, more like £300 I would say. Yes you do need to insure your stock, what if the place burns down? Rough monthly costs I'd say, for 120k worth of stock. Advertising anywhere from £500 to £3,000 depending the route you take Wages for staff £1200-£2000 again depending on quality of staff Valeting - guessing you will outsource this so £1k a month maybe? Insurance (road cover, stock, public liability, employers liability) £500 a month Rates £500 per month? Rent £1200 per month Utilities £200-£300 per month Wages for you £XXXX depends how much you want to earn Already at 8k, maybe £10k a month without any of the other costs that crop up such a vehicle prep, garage bills etc. then every 3 months the VAT man will knocking for circa £6-£8k?