Buying a dogy car

So I found a very nice car for sale in Wales. Problem is on the mot history the mileage goes up then down in one year then on one year it jumps from 50k to 80k so I don't know why this is. When I asked the lady she said her mechanic said it's an input error. The lady's car has only been in the area the past few days despite her saying she's had it 4 years? Should I buy this