Owning or renting a cart boils down to the mathmatics. In my case, I've owned my own cart for the past 5 years. Our course has cart storage sheds... with a waiting list. It takes right at 50 rounds/year to break even with the cost of owning vs. renting. I play a tad over 100 rounds/year and the cost of cart storage, electricity, and trail fee is half of what it would cost me to rent a cart for all of those rounds. But... I play one course 99.9% of the time. I don't own a trailer and have never hauled the cart anywhere off my home course.
In our region, about 20 courses went together and have a "reciprocal card program". With our paid membership, each year, we get a card that allows us to play any one of the reciprocating courses for $20... with cart. That's a heck of a deal and allows us to "sniff out" some of the other courses for minimal cost.
Few in our area own their own carts and haul them from course to course. Most courses in the area will charge a trail fee. By the time you load up... use more fuel hauling to another location... and pay their trail fee you're about as well off just paying cart rental.
Owning a cart and playing my home course all the time is really convenient. Our cart is equipped with a winter cover with lift off doors. And, we have a heater. We can hop in any time of year and play. We can leave clubs/balls/water bottles/shoes... all kinds of "junk" in the cart shed and it's there each time we play.
If you do decide to purchase a cart, find a dealer who services what he sells. We have a member who sells a particular brand of cart. If you buy from him, he'll bust his behind to take care of you if anything happens. If you purchase from somewhere else, he cantankerous enough to tell you he won't touch it and to take it back where you bought it. We bought our cart used and it's been virtually trouble free. When we purchased it, we had new batteries installed. That was a $600 expense, but we can play 36 with no problem.
Sorry... you'll find I'm a little long winded. Didn't mean to go on and on like that. You can tell, though, I love having my own cart.