Hi & thumbs up to you for making the switch

You could technically feed raw and kibble BUT never together as the digestion(rate) is totally different from one another. But you could have one kibble meal and one raw meal a day.
Instead of kibble you could feed some Quinoa and cut back on the meat. Rice is ok but its very starchy (810 gramm pro kilogram). Quinoa is healthy and not a grain (its a seed).
Keep in mind his food will only cost less the older he gets (once he passed puppyhood and teenage growth spurs). We sell some of the Primal Tubes for as little as 17 cents per ounze. Does your pet store offer the 5 lbs tubes? These are a little cheaper than the patties/medaillons because you would have to cut it in portions and refreeze it,since it pasteurized it is absolutely fine and isnt actually too much work lol