Computer v. phone data

[king1]

I'm with Spark. Computer Basic wireless data is $45 for 40gb or for another $10 is 120gb. The 40gb is nearly but not quite enough for us and I'm going to move up to the 120gb plan soon and happy that it's good value.

On the other hand, my prepay phone is $40 for 4.5gb and then I still have to use a separate plan for phone and text (neither of which get used much). I see that monthly contract plans are better and it's probably time to go that way as I need about 10gb per month.
KG 
I was just wondering why the phone is so much dearer than the computer for what is essentially the same service - wireless data via a modem. Are they justified in charging more for phones or is it just because people are willing to pay? And yes, I've looked at other companies and while some are a bit cheaper from time to time, the basic structure is still the same.

My first thought is why are you using so much mobile data, emails and web browsing won't use nearly that,  video is the main data use culprit.  

Do you have your phone/tablet etc set to use the wifi at home when at home, rather than the expensive mobile plan?   Unless you watch a few videos while away from the house I can't see how you would use that much data TBH.

And as for why, probably much the same as LPG, cheaper when filling the car but costs more for filling the 9KG bottle, same LPG.  Different market, different cost...