I'm gonna chime in here.

I think you need to change your mindset from looking for "cheap" arrows to get your "technique and practice down". To me, you are setting yourself up for failure. Cheap arrows are just that and may lead to frustration and possibly poor form. For instance, what if these cheap arrows are bent, not properly spined, fletched wrong, incorrect length, etc. The list can go on.

I suggest you get a half dozen of the least expensive, brand new arrows you can afford. Get them cut to the proper length and fletched with bright fletching. Buy field points that are the same grain as the broadhead you intend to use. As mentioned before, Gold Tip makes quality arrows in several price ranges as do other manufacturers. 100% carbon arrows will bend, but won't stay bent. Any arrow with aluminum in it may stay bent. So, I suggest carbon arrows for now.

If you are missing the target, move closer. There is no real reason to miss the target butt unless you are screwing around and not taking it seriously unless your equipment is malfunctioning. I don't think you are taking this seriously by bouncing arrows off of a concrete wall. Don't get me wrong, I've done it myself. But, I prefer to ruin my own arrows by hitting them with another arrow. That's when you move to a multi-spot target so you quit shooting nocks off.

Go to a pro shop. Buy a half dozen from them. They may let you have a half hour of range time. They should have a complete wall that is target butt. Get a lesson or two. Find a club and shoot with others.