If you have good eyesight,you may be able to interpolate (guess!
) to maybe 200,but I agree,for most of us
half a small division is "it"---hence your "80 values".
But this is the useable resolution,& can't be compared with the "number of values" the device displays.
An analog 'scope still
attempts to display an infinite number of voltage levels ,but is limited by instrument linearity, noise & beam diameter.
For the same screen size,a DSO won't be any better--it is still limited by our vision.
We are the limiting factor,when it comes to visual interpretation of the 'scope display.
A larger DSO screen will allow you to see better than half a small division,allowing you to make a closer "guess".
Even so,resolution doesn't help if the accuracy of the reading is lousy,which
is ,perhaps a point in favour of a DSO,as the ADC steps may be more accurate than the linearity of the analog device.
If it has a built in voltmeter function,it will be nearly as good as a "crap multimeter",but that is a different argument.
Where both types of 'scopes shine is in seeing things that even the best DMM has problems with,
I would suggest that you need a DMM to set the volts correctly,& an Oscilloscope to check for any crud which shouldn't be there.
By the way,how accurately does the voltage adjust control on your power supply let you set the output?
How stable is it after you set it?
In most cases,you could probably get away with the "crap multimeter".