Your parents buy the property, using cash, debt, or whatever combination they choose.

As of this amount and I live in CA, is it worth for me to this chase debtor?

and right now many of those wont "cash flow"but they might "cash flow " with 70% debt or 60% debt. or simply pay cash everything cash flows then. thats what I see my clients doing in the day of BRRR with no cash in the deal thats getting more rare and rare.. but we just did one for a client and they ended up with 12K cash into the deal on a 250k prop that makes a little bit of drip income  IE cash flow. 

The notice shall be sent by postage prepaid United States mail to each tax notice party and each tax sale party whose interest would be shown on a thirty-year mortgage certificate in the name of the tax debtor and whose interest was filed prior to the filing of the tax sale certificate.

A cash out would make sense if you are planning to pay off high interest debt or buy more cash flowing real estate. 

A Nolo Press article says "The creditor can also require that you bring certain types of documents to the debtor's examination, such as tax returns".

Inflation is loved by big debtors (US Government) and abhorred by savers.The Federal reserve keeps interest rates artificially low to benefit the drunken sailors (US Government).

Mortgage interest expense deductible on Schedule A is only for acquisition debt or debt used to improve primary residence.

The lien attached to every property owned by the debtor in each county where it was recorded.

There are also demand letters that can be written for proof of debts which if written properly give the debtor and bureau a certain number od days to respond/proof or they get deleted.