The Husky / Viking / Oregon / ? rubber boots are the most affordable, but can get heavy and hot. Depends on where and when you are cutting. I had a pair of Husqvarna branded leather boots (made in USA , but NLA) but they did not fit me right. It's hard to find chainsaw protective boots locally, and it's hard to try them on mail order.
Some of you guys who live near active logging communities will probably have an easier time finding them. Most of the safety footwear stores around here give me blank looks when I ask. Some of the chainsaw dealers tell me that they can order the boots, but again, hard to do without trying them on.
I once wrote Husqvarna US and suggested that they make at least one dealer in each metro area a 'stocking dealer' (no pun intended) so that people could at least try on the boots. Presumably, that dealer would also sell a lot more: win/win/win.
Philbert