You can get really good used tires for low prices at some tire shops where some particular and careful people regularly buy/change to new tires after existing ones are only half or a third worn.
Oh I know Bill. There is a good tire shop not too far away but when money is tight the house payment comes first.

BTW there is Eurasian Millfoil where I am going. I sure don't need to bring that back to the ponds!