Some factors affecting costs are: - how small the units are - a 1500 sq ft house will be much more per sq ft vs. a 2500 sq ft house, similar to (10) 1 bed units will be much more per sq ft than (10) 3 bed units because the more you stuff into a smaller box, the cost per foot goes up, and you still have the same costs of a kitchen, hvac, foundation, etc. but you're spreading those same costs across much less square footage.

What I also recommend is also factoring in soft expenses that you are budgeting for but have not yet spent.

This is also impacted by how old your home is, so that was likely a factor for me.From what I can gather, it's best to increase my personal liability for now and require the tenant to get renter's insurance to secure their own belongings. 

It sounds like you've already invested a lot in rentals, about $14,000 when you factor in your upcoming projects.

HVAC duct work insulation is also deteriorated.No vapor barriers installed eitherSome fungi/mold growth notedPlumbingMultiple small leaks under sinks and from bathtub and toilets.House has Polybutylene plastic plumbing which is dangerousMain shut off valve is damagedElecticalSome small exposed wiring and bad splicing.Whole house has no GFCI's or grounding outletsInteriorMoisture spots on ceilingExteriorLose Vinyl SidingDoor Jams and Window trim have moisture damageDriveway need replacementRoofingMinor leaks noted in atticRecommended to replace roof covering, but not whole roofSome fungi growth noted in roofSo some of the question I am trying to tackle with this work is:How much should I budget for the main issues listed? 

With rehabs you can get to significantly lower purchase prices and typically the lender will just be looking for  a100k+ ARV so that you can refinance out of the loan once rehab is completed (100k as-is value is pretty standard for DSCR loans).With rehabs experience is the biggest factor to LTV and rate so partnering up with someone for the first one or first 3 will get you significantly better terms (working in the same area can also provide benefits in terms of LTV).

@Karl Kauper going to guess your current PMC:1) Is having too many tenant nonpayment issues for your likingAnd/or2) Refusing to share their background checks with you, so you can make your own approval decisions to address #1 above.Several factors may be at play here that you may want to consider before being trigger-happy:1) For several legal and contractual reasons, it's pretty much NOT possible for a PMC to share background checks with an owner. 2) What Class of property do you own?

what you consider the most important factors to look at." 

There are many other factors that go into the cost of building especially in CA. 

. $3K per month as an LTR x 12 months = $36K $4K per month as an MTR x 9 months = $36K Vacancy is a huge factor.