Pricing:

In a nutshell:

Pricing depends on what it is, where it is, and when it is.
For eligible jobs, the more work you have in a row, the better the price.

If money is a problem, let me know beforehand.
I may be able to make provision for paying it off over time. If it's only a few weeks or months, there's no extra cost. Any longer is indexed with inflation. When the banksters print money into existence without backing it by material substance, it makes money less valuable.

"Can you do it cheaper?"

All depends.
Generally speaking: I can do, but availability is restricted to quieter times, warranties carry more restrictions, and you have to bring your own parts (and if they fail, it's another call out to replace them).

I'm happy to provide a quote, and possibly the options to pay it off over time if you need it.

Transparency in pricing (How rates are determined):

Employers usually pay their full time workers about $50/h (and it seems to me they offer full time work but then let them go when the work runs out, that's a whole other can of worms).

I made spreadsheets which calculate the charge out hourly rate when factoring in employee leave entitlements and core business licensing overhead costs.

Employee leave entitlements adds about 10% to the base hourly rate.
Core business licensing overhead costs adds 2% to the base hourly rate.
Simple Workcover calculations are based on 18% of the base rate (Source, Page 13)
Base rate $50/h + Workcover equivalent $9/h + Casual loading $5/h + Contractor licensing obligations $1/h = $65/h
A wider range of services means more licensing obligations.
That's where I get the $70/h from - if you regularly have a full day's worth of work.
Travel costs work out to be about $0.80 - $1.20/Km, depending on travel efficiency.
These rates may increase as the dollar continues to devalue.
I've also invested a lot of money behind the scenes to help bring you the best.

A contractor isn't guaranteed 8 hours of work a day and therein lies the problem - the shortfall needs to be factored in to the hourly rate. Sometimes there's too many rainy days, which delay jobs that involve outdoor work. Some jobs carry a high warranty risk.
At 50% billable hours, the hourly rate works out to be $140/h, hence it wouldn't be unreasonable to call for at least $140 plus parts for a short visit.

Parts and warranty:

I do put a markup on parts. This also means there's no cost to you if they fail.
For electrical, where possible, I prefer the Voltex brand. They have good lab testing and an efficient supply chain, ensuring value for money. Their warranty also means you can ring them up even if I'm unable to get there in a timely manner, and you can still claim warranty through them.
You can bring your own parts. But if they fail or they're the wrong parts, this means extra labour costs you'll have to pay.

For air conditioners, I have brands which I prefer. I also offer a 7 year extended warranty, because I do good air conditioner installations.

Typical prices:

Prices listed below are for indication only and are not quoted contract offers.
Most houses are covered, but some houses and commercial jobs may be more.
Niche services:
• Solar detection hot water switch: $250 - $800 depending on options.
• Fridge preventative maintenance: $500
• Air conditioner servicing (bedroom): $700 (Add $100 for loungeroom)
• Air Conditioner gecko proofing (split or ducted): $400
The following air conditioners include gecko proofing, individual surge protection, and an extended warranty (7 years instead of 5):
• Bedroom air conditioner (2.5Kw):  $2200
• Bedroom air conditioner (3.5Kw): $2400
• Loungeroom air conditioner (7.1Kw): $3500
• Loungeroom air conditioner (8Kw): $3700
• Ducted air conditioner (Single phase, ~16Kw):  $15000
• Ducted air conditioner (3 phase, ~32Kw): $25000 
Brand offered is Hisense.
Other recommended brands include Rinnai J Series and Kaden.
Hisense is best value for money.
Rinnai JX Series bedroom air conditioners are theoretically the most energy efficient.
Kaden are just easy to use - insert the batteries in to the remote control, turn it on, and set the temperature. By default, fan speed and heat or cool settings are auto.
Common services:
• Small call out (Parts additional): $150
• Switchboard surge arrestor: $250 (Add $200 for 3 phase)
• Main switchboard upgrade circuit protection devices: $1600 (Add $500 for 3 phase boards)
• Relocate meter box: $6000
• Consumer mains cable upgrade: $1200
• Ceiling fans (Voltex DC, white 52" with light, 7 year warranty): $550 each 
Backup power:
• Prices vary widely, starting from $400 depending on options and requirements.