It is not normal practice, no. Normal practice is that the seller would present good marketable title. However, nearly every problem of this kind can be sorted out, but it make take time, money and cooperation from both the seller and the owner of the other farm. As for how long and how much, it really depends on the nature of the problem, the possibility of cooperation and what method of rectification can be done. It might be as simple as getting a deed of rectification signed by all involved, but if the person to whom the land is registered in correctly won't cooperate, then other methods might have to be employed which might not have any guarantee of success. To get proper advice you should have your solicitor contact the auctioneeer and solicitor for the seller and they should be able to advise further.