A person over 60 should never take oral estrogen. It's quite risky. Hard on the liver and more likely to cause DVT.
Injectable Estradiol is relatively cheap. It will cost around $50 for a 10 week supply, using discount coupons which are readily available
Estrogel while, is a bit more expensive, $106 / month.
The insurance doesn't offer you much advantage, since Walmart will sell generic estradiol tablets @ $10 for a 90 day supply.
I just read that you are in Canada, where injectable estrogen just isn't available except form a compounding pharmacy. I'm not sure about patches or gel.