Overextending? Need advice from the old timers

[Hannah Joy]

I have managed to obtain 3 buy/hold properties in 3 years and am in the middle of converting the garage on the 3rd. A property just came on the market that seems like a very good deal, and exactly what I look for. I feel like I have to try for it! Theoretically I could obtain a HELOC on my first property for the down payment on this one and sit on it until I have time for reno. I feel pulled in both directions - go all in on a good deal or be smart and wait for the next one because I am pretty leveraged (and tired) as it is? It seems like such a good one. Advice from those that know better?

Property 1: 276k balance, 450k BPO, monthly cash flow average $500 

Property 2: 376k balance, 700k BPO, monthly cash flow average $450

Property 3: 420k balance, 650 BPO pre garage, monthly cash flow $550 once garage is done 

Potential purchase: 375k purchase, 75 down payment, 3 units, currently rented. Development potential to add more units. Not in the worst shape, could wait a year or two to fix up. Great location. Would need at least 100k to update. 

Thanks!