My first AR was a RRA Elite CAR Mid-length as the mid length gas system ARs are just smoother and suffer less bolt & extractor issues than the carbine length sytems do. Great rifle and like many I went through stages with it where I added all sorts of stuff and then later decided it was way too heavy and so I went for light weight, removing most of the junk I added.
In addition to removing most stuff, I shipped the HBAR to ADCO and asked Steve to reprofile it to a light weight (including a smaller gas block), shorten it to 14.7", give it a target crown, and then weld on an A2 FH to make it legal. Then I replaced the furniture with Magpul CTR and MOE and loved it's light weight and compact style.
When my son decided he wanted to 'liberate' it for his own use, I went looking for a replacement mid-length, hopefully something I didn't have to go through all the mods to get it like I wanted. The M&P15 Sport was a carbine gas system and needed all of the changes I didn't want to go through again.
Then I found the M&P15 MOE Mid Magpul and it was set up almost exactly the way my RRA ended up. Currently available as the
M&P15 MOE Mid, it's set up and all ready to go. Yes, it costs more, but my M&P15 MOE Mid Magpul was exactly like I wanted. The only mod I've made to it was to simply replace swapping S&Ws long FH for an A2 FH. Stock it makes a great light weight carbine and the mid-length gas system makes for smooth operation as well as increasing the sight radius by 2". Something to consider.
Shown here stock before I swapped out the FH. Later, I also added a custom made pistol grip like the one on my RRA above. Even today, some 3 yrs later, it's still as shown, still working great, reliable as heck, and still a favorite light weight AR.
Now that 'Hildabeast' is politically DOA, there likely won't be a frantic rush to buy ARs next year so the prices will likely stay low. My recommendation is to save up so you can get a model that's as close to what you really want so that you have something that starts out ready to go.