There’s always a reason to get a new gun, biggest being you want one. That alone should be enough. Now just convince yourself, you don’t have that one yet, you can give the 243 and 223 a break and shoot the 22-250. You can have another cartridge, in case the other two become unavailable or hard to get. You need the bit of extra speed the 22-250 offers because you may need that long shot and don’t have time to dial scope in etc. Just think of enough reasons, and buy one. Hell I have three rifles and multiple pistols I have never shot. If you don’t like it you can always sell it, that is one excuse I use to convince my self to buy one, when the urge arises. Good luck with your new 22-250, it should shoot great. Lol