I have found nothing that will take a pounding for long with broadheads. I would say get some burlap bags and stuff your old target insides into the burlap. I got two burlap bags out of my last yellow jacket. Use those for field points. Then get a decent broadhead target and use it only when needed.
The best combo target I have ever had was a 24x24 original block. I shot that for years until I finally cut the bands and restacked the best layers to make a smaller target, but usable for a while longer. I shot it sparingly with broadheads and used only replaceable bladed heads with practice blades and two blades with sloped backs so they pulled out with minimum damage. Square back broadheads, vented blades, and bleaders really tare a lot of material out of a target when you pull them. I got 6 years or more out of it before restacking it.
The Rinhart targets are great. I love them for field points. I have a wood land buck now. Small, but reasonable size vitals and low cost. I will not be shooting it much with broadheads. Just a little before hunting season at hunting range so I don’t chew up the main body.
The Rinhart 18 in1 is a great target with a 1 year warrantee. I shot up 4 in under two years using them as my only target. I then decided to slow down on shooting them due to cost. At about $125 target cost a year it was not too bad, but I didn’t see the need to spend that much. Now I get them and shoot them sparingly using them for tree stand practice, portable travel target, and for broadheads. I shot the last one on and off for 6 months from spring to end of summer with field points, and did most of my practice on the burlap bags. I then hit it with pre season and during season broadhead practice and that did it in. I got the replacement, and now I am going to do the same this year. That will get me a decent target for about $45 a year.
The best thing I have seen so far looks to be the blob target. I think that will take a major broadhead pounding, but shipping on a decent size one is a killer. And it is not portable at all. I would have one if I could find one local. Maybe you can find on in your area.
I just got a horse stall mat for a back stop in my barn. Very heavy 4x6 and about ¾” or a little thicker. $35 on sale. It really stops the field points. I am thinking seriously about getting another and cutting it in three sections and then trying to glue it together into a 2-2 ½” thick 2’x4’ block and then using it for broadheads. Maybe cut a deer shape or just put some cardboard deer silhouettes on it so I can move the kill zone around. Not sure yet how well it will work, but it could be worth trying it for the cost.