You dont need a Kestrel for ballistics. If you have a newer phone you can get an app that will help you out. Ive been shooting 1k for 3 years now and i havent opted for a Kestrel (yet). I watched a few videos on how to judge wind, so now i sit at home and judge wind. That skill you'll want either way.
You don;t need a chronograph, but it will help with load development. If you have a crazy ES and don;t know it, then you could be trying to fix things that are caused by that. Knowing your MV is helpful for tuning your ballistics too. but you can adjust that on a ballistic app, without knowing you initial, its part of truing your ballistics either way.
For reloading, an fx120 (Cahrgemasters are overrated IMO) setup with auto throw, etc would be nice... But its not necessary. To get around spending huge money here i bought an old scale that has the same tolerances as the FX120. It cost me $100....but its not compatible with auto throw... so theres that. I just use my old thrower and hand trickle up. It takes longer, but is just as precise.
I mean you can find anything to upgrade to help you out. And once you start buying stuff you;ll continually want to buy more, and more, and more... Do you need a good RF? That could be an area to start.
As for a bipod its all personal preference. I have used a harris for 10 years and it just works. Once you know how to use it you will appreciate the ability it provides. Is it the flashiest and newest, nope. Does it work pretty damn well for its purpose (price). YES.
Good triggers are nice, but if you already shooting half moa, it wont get you too much more improvement.
Those are just some of my opinions on how to get more useful items for less money. I have a chrony digital chronograph. Not the best for anything..but when I went to true my MV at 500 yards i found that I didnt need to change the MV. I was surprised that it was spot on. Do i want a labradar, of course. Do i need one... Nope.
I keep telling myself that someday i'll be somebody by having the best of everything (no i dont) but at the end of the day 2 things will help you the most. Practice and ammo. Those 2 things are worth more than all the others combined.... But you wont realize that until after you've spent the money on the rest of the those things.