Purchasing in San Diego 4 working parents preparing 4 retirement

Hi BP community! My parents have not saved enough for retirement and are currently renting. To help them out I'm thinking of purchasing a 2br2ba or 3br2ba REI with 25% down. The max purchase price is around $400k to keep rent closer to $2000/m. The title will be in my name and they'll rent it from me. The plan is to keep rent at a minimum for them. They don't have the income or credit to purchase on their own. To supplement their income, because my mom doesn't work anymore, is to do home stays or STR. This is why we need at least 2nd bedroom and bath, near public transportation, and can't do a senior retirement community yet. I know prices are high in San Diego and we're looking specifically north of I8, up to 10 miles east of mira mesa and south of Escondido. It doesn't have to be move in ready and I can afford about $30k in reno on top of 25% down (100k). I'm hoping others have information, ideas, advise and strategies that we haven't thought of yet. This is a bit of a hail mary but you never know. Thank you all!