Potential deal with foundation issue

[Sheng Ma]

Asking for opinions as I'm a new investor and have only a couple of deals under my belt, looking to buy and hold. Property is a 2bed/2bath with foundation issue (needs R&R) quoted at $60k - 4ft extension was built into the master bedroom many years ago and does not have a foundation (only blocks). No overt signs of bad foundation (drywall cracks, doors plumb, windows open fine) but due to settling the floor has a variance of 1-3" over the span of 10 ft. 

Additional permitted 1/1 unit which was built ~10 years ago and is in decent shape. Also has a decently well constructed studio in back of garage which is not permitted, may be able to get approval as ADU but not going to include in my calculations.

$445k purchase price

Repairs (mostly cosmetic/some termite damage/appliances) - $20k

ARV - $530,000

Rent - $1500 (1/1), 2/2 ($2000), total monthly rent $3500 + studio AirBNB if I can swing the permitting piece. Will plan to self-manage.

PITI - $2400 + 10% maintenance/vacancy/misc = $2700/month in expenses.

The deal obviously will cashflow and this is in a very hot market in CA, where cashflow generally doesn't happen easily. I don't have the capital on hand to fix the foundation issue right now (could stretch it if I deplete emergency funds but not willing to). My plan is to purchase and do the cosmetic renovations, ensure the unit is structurally sound, fix the foundation in 3-5 years and re-do the drywall/paint etc at that point. It has been structurally sound for at least 10 years since the addition was built, foundation company even mentioned in passing it'll probably be fine structurally for 10 years if I don't mind the sloping floor slowly worsening, but no guarantees on timeline.

Is this a terrible idea? Has anyone had prior experience with foundation issues? On paper it works out but I'm hesitant due to the scope of the issue and would love to hear what your thoughts are!