getting title cleared with a lot of heirs seller doesnt know

[Shella Sanders]

I hv a house in oak cliff, Dallas under contract for 10k. found out there are 25k in back taxes. which still works. I am dealing with two grandsons. The house is still in their late grandfathers name who died before they were even born. Their father lived in the house until he died 5yrs ago. when I look on the county website dcad. all i see if the grandfathers name. however, when title co pulled title, the grandfathers wife and her second husband is also on title because the wife did submit death cert for the grandfather and changed it into her name. so it went to her second husband after she died but i don't see her death cert or any record of him probating it.  so now I am told I have to do affidavids of heirship for the grandmother and also her second husband. AND the grandmother and second husband had like 7 kids who would be heirs as well. who the grandsons i am dealing with do not know at all and assume they are probably all of or mostly all dead. I have tlo skip tracing so i have tried to skip trace them i think i found half of them and the other half i am not sure are the right person.  Is this possible at all to do or should i just walk away. Im sure me and the grandsons can get the affidavids done for the grandmother and second husband but i don't know where to start with finding out about all those kids. and the title co attorney wants to charge me $150/hr to help with no gaurentee's. any advise is helpful. I can sell this house for 55k as is probably if i can get this cleared