In the long-term, you'd be smart to establish Combined Shipping Rules so that you don't frighten away prospective customers.
To say in your description that you 'combine postage' is insufficient because it is non-binding. You must go into your settings and set-up rules. Doing this will show buyers that you offer combined postage discounts in the places that matter, and also reduce the sticker shock and abandonment when buyers get to the cart.
Also, unless you dispatch from a remote or northern location, your handling fee or non-discounted postage rate is probably higher than it needs to be. Ship through ebay for discounts on postage available to all sellers via Shippo, through Paypal Shipping, or via Canada Post Snap Ship. You shouldn't be showing the counter rate, it's not what you pay. Buyers are turned off by postage in general and most things can ship across Canada for less than what you're displaying for postage costs. That is, unless you're shipping from a remote or northern location in which case you may consider the higher-than-usual-cost-for-postage on your listings to be a disadvantage you must plot against. Perhaps through subsidization.
But, more important, the combined postage rules. Buyers today (except in a few subsections or categories frequented only by legacy members) want to pay and go. Not wait for an invoice and come back to pay later. This is established by ebay's Best Practices.
Please request assistance if you need help establishing Combined Shipping Rules.
