The 5-10 it gets heavier and a lot busier, and 10-15-20 it really is untenable to self-manage especially if this is not you main business like a person buying their own rentals and building it like a small business. 

Investment Info:Small multi-family (2-4 units) buy & hold investment.

Or should I just exhaust the heloc and keep buying houses? 

I would also add, a contractor that you can buy materials for and they know how to put them in with little to know direction (reduces the management time of the project).

He bought his first couple houses in the first year or two and didn’t buy much for a few years.

One golden rule I follow,if it takes a long time to fix/replace when it breaks, don't buy a cheap one.Imagine, this thing breaks in the middle of your peak season and the people who can come out to rebuild are 2 weeks out....It takes at least a day or two to build something like this even if you are super skilled.

Direct buy? 

These increases are not direct costs like buying toasters from China, but rather input costs.

Depending on the type of rentals you have, pulling out the cash in a refinance might be the way to go to buy the mobile home park.

My wife and I also invest in STRs and I spend a lot of time working over the best place to buy our next property.I've been looking at Packwood recently for a client.