The only place online I have seen .35 Rem ammo is Cabela's. They only have Winchester Super-X in stock for $29.99/box and Hornady Flex-tip for $34.99/box. Is that an average price for factory ammo or is that a panic/COVID price? I was thinking about starting to reload 12ga for my trap gun so maybe I'll get into reloading for this gun too if that is a normal price per box.
There are plenty of places with inventory. Try AMMOSEEK.COM.
Generally speaking....figure 25 to 35 bucks a box of 20 rounds. Hornady LeverEvolution can sometimes have availability year round. But Federal, Remington and Winchester availability tends to coincide more with seasonal production runs that take place around hunting season. Once it is gone, it can be hard to find until the following year.
Reloading can certainly be a good idea. You likely won't save money necessarily, so much as you'll probably shoot more for similar cost.