Expensive market - how much downpayment is too much?

[April Laspinas]

I live in one of the most expensive yet smallest countries in the world - Cayman Islands. I’m a beginner in RE investing and up against cash buyers on million dollar properties in the market. So traditional lenders i.e. banks are not very friendly to newbies. 

I have analyzed tons of deals however conventional loans at 20% Downpayment hardly yields positive cash flow due to how expensive the market is. SFH averages 450-650k. My question is, if I can afford putting in 30-40% downpayment to yield positive cash flow, is the risk too high? That would mean putting in 150-250k in downpayment alone. Appreciation is likely due to relatively growing market but as a first investment I would like to get guidance on investing in expensive markets. There's no BRRRR market either due to how small our island is. House hacking is not possible for me as I have kids.

Do investors really put down that much downpayment in expensive markets?