There are several YouTube videos that guide you on making one for a fraction of the cost that you would pay from buying one. I've watched a few of them and there are different designs you can follow. Some pretty good ideas out there and all the parts for it can be obtained at a Home Depot.
Otherwise, as soon as I can I'll check my catalog. There are several manufacturers that make them with prices ranging from $100-$500.
I picked up a 2ton engine hoist for cheap at a garage sale, a metal fence post from Hopeless Depot, and with a few straps I made mine for around $70. Works like a champ, and I can easily take it off, or put it on by myself in no time.
I use an inexpensive Canadian Tire 1,000 lb. rope hoist anchored to a tree in my back yard. I'm sure there are similar ones no matter where you're from. They look "cheap" and instill "0" confidence but they work great. I've done my LJ with one. I'm not sure what the weight difference is but they're definitely heavier than a TJ top.