A saddle is important, its what makes saddle hunting comfortable or not—I would not personally skimp there. You need a way up and down from the tree, unless you are braiding your own rope or making your own sticks thats not a diy proposition. But the tether and linemans belt take all of 12 seconds to make. Buy if you want, use a ropeman or other grab if you want, but a tether is literally a short piece of rope with a loop in one end and a couple simple knots—buy 8mm or 9mm accessory cord or 9 or 10mm static rope from an outdoor store or online, tie a loop in the end, and you’re done. Linemans belt isnt much more than that either, its a short rope with a prussik or rope grab on one side. No reason you cant make your own, both are 1-beer projects and will not cut into your summer scouting. It’s also not expensive enough that you are going to save a lot of money unless you already have material from something else.
Re: Prussiks. If you want a rope grab (generic term for ascenders and stuff like a ropeman) to be as strong or stronger than a prussik it has to be rated to the uiaa 12841-A standard (NOT en567, and not 12841 b or c). A device rated to the En567 or uiaa 12841-B only has to hold 4kn (900lb) maximum before it damages the rope—these are not designed to be primary safety devices, and when they fail they generally strip the sheath off the rope they are on. There may be a few products that carry a manufacturers rating higher than 4kn, but just be conscious of what these things are actually supposed to do and make sure you arent relying on one for safety without being aware of what it will and wont do.
A 3’ piece of 6mm cord tied in a loop costs about $3 and weighs essentially nothing, is silent when it hits other gear, packs into a tiny space, has multiple uses, and will hold several thousand pounds on a nylon rope. A ropeman or grab costs about 10x the price, is generally only tested to hold a 900lb load before it strips the sheath off a rope (which can happen just taking a very short fall onto a slack tether ), makes noise when it hits other gear…it is easier to tighten, questionably a little easier to loosen. I would suggest if you are pinching pennies start with a couple prussiks—it does everything a ropeman does, in some cases better. If you decide you want a ropeman you will still likely end up using a prussik once in a while even if its a spare, so good to be familiar with it.
