I have a bit of a different position on DRO’s. Yes get one on your new mill whatever one you purchase. It will be a great “aid” in your machine work. You get what you pay for so match the quality of the DRO to the machine you purchase, maybe one step higher. Remember the machine you buy is going to move around when you cut, how much depends on its rigidity. Since I started in the machining hobby in the mid 70’s, I have acquired 5 milling machines that I kept, two with DRO’s, each of these five machines act differently when cutting. The two with DRO’s let me cut a whole lot faster, but when you get close to the end it’s time to get out accurate measuring devices. Of course it depends what you are making.
The point is do not assume the DRO is going to make your machine any better than it already is. The DRO is just an “aid” that makes cutting and measuring easier, as long as you remember which side of the center you are on or which side the cutter the zero is set etc. You still need to acquire all the mill machining skills i.e. what your mill does with a climb cut, how much of a cut can you take, how to compensate for your vise, if you have variable speed ( another worthwhile “aid”) how does it affect the cut if changing on the fly, power feed control another “aid” that needs understanding, cutting dry or with a lubricant, and then add in the with or without the DRO.
BTW you mentioned the possibility of a lathe, that’s a whole different set of possibilities with a DRO, again an “aid”. I have one with a DRO and can make stuff at least 50% faster as long as you pay attention.
You will enjoy a nice heavy mill compared to Taig you mentioned, and after a few projects wonder how you got jobs done without it. You need to pay once and “cry once” or you will pay twice and “cry louder”! I think that has been inferred in the posts.
Good Luck and enjoy your retirement gifts – be generous to yourself.
Bob