A good rule is don't buy from auction unless you have your OWN workshop and can spin the spanners YOURSELF .
Out sourcing mechanic work can be and is VERY expensive hobby .
Doesn't look much per job till you reckon 50 water pumps , 50 brake discs , 20 gear linkages , 30 clutches and the list goes on
Same with Valet work do it yourself , Doesn't look much till you x 60 x £50 = 3k at year end
This 3k and more will be needed for next year because stock Goes UP in price year on year , what you pay 2k this year will cost £2,300 next year if your lucky so again £300 x 60 cars and the following year you need an extra investment of £18,000 to stand still . Lots of people forget this equation and go backwards , its why we NEED Profit above wages .
Business rule ;; Don't take all your profits out thinking your doing well
But good luck with the venture , stick at it and its fun , takes a while to get the stock and the funds to make it work well but its fun getting there and great fun when your cooking on gas later ,
Spend wisely , Earn profits , Profit is not a dirty word .