I have a trolley (a two section silver trolley with a removable case as the third section). I like it very much, BUT it's required a little alteration...
The stand on the bottom is about two inches too short to be of any good - the trolley just falls over if there's anything in it. I put it upside down, drilled holes though the bottom, and screwed a wooden brace to act as a stand. So far it's working a lot better.
It fits upright in my car boot if I don't put the removable case on it. The case sits next to it in the boot and keeps it from falling over when I drive. I agree it can be heavy, but it depends on what you put in it. I like the professional look of it - I wouldn't walk into a client's home with a bunch of plastic bags!
I also have a pedi bag (with a shoulder strap), and a waxing box, as well as a portable manicure table and a massage couch. I only take in what I need - my carrycase holds all of my absolutely necessary tools and supplies, that I use for every client. Then I just grab what I need depending on the service. If I'm serving a client and they ask if I can squeeze in an eyebrow wax, it's just a quick trip to my car to grab my wax box. I also have some bungee cords that I can stick my wax box to the top of my trolley (I have a shoulder strap on my carry case so it doesn't have to go on the trolley too).
This is working well for me - I shopped around and got a good price for it, but I do agree with the other posters to check out places like B&Q. Think outside the box! Don't just shop at beauty stores - I know a tech in the States that uses fishing lure boxes for her supplies, and I store a lot of my things in the little cases the airlines give business class customers (my husband flies a lot for work). In the past, I've also used a large rolling duffel bag for supplies - the only disadvantage being the weight!!
Anything except plastic bags!!!