Quoted from xTheBlackKnightx:

These dollies listed on Ebay are the same lift based on specifications.
They are the not the same level of "heavy duty" as original WICO dollies, based on cased framed construction.
WICO dollies last forever, and were the industry standard for decades.
To understand, there are various types of "lift" mechanisms used on pinball machines.
Dolleys, lifts, tables all have similar functionality, but not necessarily designed optimally for pinball use or at least not without modification.
The "Pinball Lifter" is a much cheaper version using a Sears motorcycle jack, generally modified with a wood slat frame for additional height.
http://www.sears.com/craftsman-motorcycle-atv-jack/p-00950190000P
They generally have a good warranty.
Here is another serious dolley, that outperforms WICO and the HFLT.
It is called the "Yellow Jacket" as is an EXCELLENT lift mechanism and ratio of weight.
http://www.pinballmedic.net/yellow_jacket_pinball_dolly.html
Many collectors just build their own.
http://www.biltronix.com/pinball_dolly.html
Its cheap, and easy to construct.
The only reasonable objection is bulk, not weight.
If you want to be "really cheapo", you could just buy a hydraulic car jack, but I don't recommend that direction.
About the only advantage is portability, but you cannot move machines with that device properly.
You do not aggravate back problems, if you use any pinball dolly/pinball lifter/lifting table correctly.
I have back problems from combat, and do not have issues with my WICO which I have used for nearly 30 years.
If a new collector owns more than half a dozen machines, a dolley is not an optional pinball accessory.