We did the demo and removed the carpet and padding to try and reveal the cement slab floor. 

Taking things down to the studs with tile over 1/2" cement board is best.

I got a GC to come in at that point and he did a great job with some rebar in the hole, then we filled it with some 6 sack from STAR (rolling barrel cement on a truck). 2 cubic meters of cement later, the job was done (probably $3k).

There is a cement board "skirt" with occasional louver vents to keep the critters out.

The toughest part is getting in there, getting material in there and working. it is a labor intensive job, which would be your main cost. 1st thing is to clear all the debris that the inspector said was in there then you would have to temporary support the floor joists as you replace the beams that are cracked/ broken. others you can make a 2'x2'x1' deep footing right next to the block, once that hardens pot a small post or cement in a new block to support the beam, then remove the loose blocks. 30K seems like a lot, but it could run you between 10-20K, the hardest part would be finding the contractor that would want to do the work, i have worked in bad, tight spots and know how it could be, i wouldn't even take on a job like that.

Is there a school or a cement plant going in across the road. 

downstairs would be 1 bedroom, 1 bathupstairs would be a studio with a separate bathroom, walk-in closet, and small entryway roomfeatures I think are "pros" for potential tenantsfront porchfenced yard (with cement and grass)walking distance from Blue lineparking (one car garage, space for a car on the cement part of the yard, and permit on the street)basement and a bunch of storage spacecentral air conditioningfeatures I see as consdownstairs, the kitchen and bathroom are outdated (both are functional, but they look like a grandma's house, haha)Sorry for being so long winded, but I wanted to give as much information as possible.

Wood Structure with Hardie Cement Fiber siding.

We live in WNC now and trying to decide what would be best for us for this property.It is a cement block 2 bedroom home (but could be made into 3 bedrooms) with 1 and 3/4 baths, Florida room and garage.

That includes framing, cement work, electrical, plumbing, grading everything you can.