DannyDarkoArts

To buy the plot of land in Morthal you can be any level, First you must complete 'Laid To Rest' quest and then assist two people in Morthal. The easy way to do this is cut wood and sell it to the lumber mill and do this other quest delivering a note for Idgrod the Younger to Danica Pure-Spring in Whiterun. From there you should be able to buy the plot of land after becoming thane.