When I represent a home BUYER who wants to purchase on Contract, I advise the seller give them a deed and then take back a promissory note secured by a mortgage if the seller demands one. When I represent a SELLER I advise a land contract with no deed given nor placed in escrow and that the contract be NOT even recorded.
If you get 100K down, give them a deed and take a note for the 30K balance SECURED BY A FIRSTTTTTTTTTTTT MORTGAGE youre not in too bad of shape (if yours is the first mortgage and its recorded and theres no other junior mortgages) buttttttttttt youre safer if you enter into a conditional installment land sales contract,,,,,,,,,,,DO NOT give them a deed,,,,,,,,,DO NOT HAVE THE DEED PLACED IN EXCROW,,,,,,,,,DO NOT have the contract recorded,,,,,,,,and promise them a deed and free and clear title upon payment of the 30K
HOWEVER if they are paying that much down the buyer prob wants more protection and wont go for that deal (which is much safer for you) although its prefectly legal.
Be sure yours is the FIRST mortage and I wouldnt want any others,,,,,,,be sure the mortgage is properly signed notarized and recorded,,,,,,,,if they dont pay its up to you to FORECLOSE on their interest and theres likely a equity of redemption period,,,,,be sure the taxes are kept paid and the insurance and if not be sure you pay them (add to buyers unpaid balance)
NOTE this is far too important and theres wayyyyyyyyy tooooooooo much at risk so you need to consult a trained PROFESSIONAL a local real estate attorney AND DO NOT PLACE MUCH VALUE ON LAY OR EVEN UNRESEARCHED PROFESSIONAL (including mine for sure) "OPINIONS" POSTED HERE....
Best wishes n God Bless
John T Country Lawyer