Health insurance.

Have you tried "Googling" for coverage? Healthcare insurance in the USA costs just about twice as much as in Canada. I found this website that seems to offer several plans though I have no experience with them and am not connected in any way with them: https://www.americanvisitorinsurance.com/travel-insurance-over-70.asp
Another find:
https://www.internationalinsurance.com/compare/global-medical.php

These are just a couple of websites I found by searching. Do your own diligence and research.

With Tour Med

LOFAT36 wrote:
We live in Canada and plan to go to Arizona for 6 months as we’ve done for the past 7 years.my wife recently has a mastectomy and many years ago had a bout of asthma. As far as myself, I’ve been on blood pressure pills for the past 20 years. However, this past July we both turned 70 and for 6 month insurance they want $3400 to cover both of us. This does not cover anything related to asthma or cancer for my wife. Does this sound reasonable ?

Just discussed on here.
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29969335.cfm

You're probably not far off, considering your ages, recent and past pre-existing conditions, and length of trip. There are too many variables to say for sure, and who you're dealing with might be a major factor in determining a price for you.
Who are you with? That's probably the easiest fix, just change insurers/underwriters.
In the linked thread, there are some good suggestions/alternatives.
Bottom line: It costs what it costs to make sure you're completely covered, and traveling without it, could lead to catastrophic financial liabilities.