Such as AC/HVAC units, roof, garage door, yard work, septic, foundation issues, new panel etc etc. each market is different but if you don’t have anyone locked in you have used and trust on price in your area then get a really safe margin of profit and use this scale to help your offer.

If the property hasn't had any updates you're going to potentially run into issues such as old aluminum wiring, old fuse panels instead of breaker boxes, no duct work in the house, old inefficient windows, and no insulation just to name a few.

I performed ALL other work by myself with occasional help from Family members: Complete Electrical Revamp (New wires, Panel, Meter Base, outlets, etc), New Pex plumbing, Shed revamp, Landscaping, Windows, flooring..and basically everything else. 

The only theft at that point was someone had snipped the wiring at the electrical panel, taken the copper from the hvac and some holes in the walls.  

It is not a problem for me as for my house I have an inverter, batteries and a generator, and putting in solar panels.

Bill S.That also covers pre fab, panelized and kit built homes and yes there often is a great deal of complexity clarifying the two.

Very nice looking heaters:https://www.amazon.com/DeLonghi-HMP1500-Mica-Panel-Heater/dp/B005MMN75G/ref=sr_1_2?

My AC evaporator luckily has an access panel that is easily removed and then a service plug in the side panel of the coil (plastic disc wedged into sheet metal) that I was able to remove, liberally spray down the coil on the 'incoming air side' with cleaner bought from lowes, and carefully spray some water onto the coils from the easily accessible 'outgoing air' side to back rinse after waiting the recommended time. 

My PM scheduled a yearly inspection they my property and uncovered these issues: Sprinkler eroded a hole in the dirt near the houseFascia has a gapTree needs a trimKitchen cabinet door won't close, replace hingesPressure wash concretePool Screen Panels torn, need repairScreen door latch needs replaceThen he quoted this work out and it came to $1145.

Why would anyone need access to an electric service panel?