The last three pair of rubber boots I have purchase I like very well and they kept my feet reasonably warm, very dry and were comfortable; however, all three has split on the front were they bend on removal and putting them on. One pair was Cabelas and the other two were Rocky.
X3 on LaCrosse...I use to use something called IIRC sportsman goop on my neoprene waders...should work on rubber boots...also you should store your boots away from heat and sun light in the off season.
Only fools fight in a burning house...Day of the dove
Is there a glue that will repair them... are in very good shape except for the tear? Or is that like asking Mrs Lincoln, " Other than that how did you enjoy the play?"
If they are rubber boots, try inner tube repair kit glue, with a cut piece of inner tube rubber for the patch. After curing, fill up the boots with water, and set them on newspaper or paper towels for awhile to check for leaks... Or find a bike shop and see what they charge to patch them for you.
As for new, I don't care for the 800-1200 gram insulated boots. Too heavy. Last year I got a pair of Muck Fieldblazer 2 boots and love them. Lightweight, and comfy fit. Them and a pair of wool socks over synthetic socks worked well during winter hunting. If toes do get chilly, I just use a couple of the stick on toe heat pads. I paid $79.99 on sale at Dicks for the Mucks.
I see the problem they are splitting right above where they are not reinforce with a second layer of rubber. I see some of the other brand mentioned above are reinforce with a second layer higher up the front.