Pretty sure this will be divided into two camps: 1) guys who will steer you towards a carbine length gas system and 2) guys that will steer you towards a mid-length gas system. If you aren't family with the two gas systems I'd do my due dilligence to help me decide:
https://partner-mco-archive.s3.amazo...1527866983.pdf
https://www.guntweaks.com/mid-length...s-systems.html
After that the groups will probably be divided into 1) those who suggest a conventional FSB (front sight base) rifle; and 2) those who suggest a free-float foreend. Generally speaking with a FSB rifle, the only sight you will have to buy is a rear sight; generally speaking with a free-float you will have to buy both front and rear sights. If you choose to use an optic (you should) you can skip the sights on the free-float, although many recommend you still install a set of BUIS (backup iron sights). You can put an optic on a FSB rifle, for me the only factor is making sure I get a mount that gives me a lower 1/3 co-witness. (co witness explained:
https://www.youtube.com/watch?v=ogX-cIx9hpk ) I still put a rear sight on a FSB rifle.
A FSB rifle will generally come with mil-spec style handguards. These often provide problematic for attaching a weapon mounted light. Perhaps the easiest button to solve this problem is to purchase a set of Magpul SL Handguards:
https://magpul.com/moeslhandguard-mi...obal_color=118
Advocates of the free-float will point out that there are many option for mounting extra equipment on the free-float. This is very true.
So, regardless of which type you choose you have additional expenses before you hit the range:
FSB: 1) Rear sight; 2) Optic; 3) probably new handguards - depending on rifle manufacturer
Free-Float: 1) Rear sight; 2) front sight; 3) optic (as mentioned you can decide to initially forego BUIS)
The next division of groups, and perhaps the most contentious one, will be over recommended manufacturers. There are numerous high-end manufacturers which, unless you are a multi-millionaire, are probably going to be too expense for a first AR. The next level I think of as boutique level manufacturers, they offer good quality, and are pretty much priced competitively with one another. In this group I would include BCM, Centurion Arms, Sionics, SOLGW as examples.
The 'middle' level is arguably occupied by one manufacturer - Colt. Generally Colt's prices are slightly lower than the boutique level. One point I should make here is that Colt is a mass producer of the M4/AR, the other makers we've talked about thus far do not truly produce in volume.
The next level are lower-priced manufacturers. Several of these, such as PSA and Anderson, I consider mass producers. This, to me, is wear the contention is greatest if you are making decisions on a 'what gives me the best bang for the buck.' For example if we want to consider FSB rifles here are some comparisons:
Colt M4 - $1099
https://www.colt.com/detail-page/col...-4-pos-stk-blk CARBINE LENGTH GAS
BCM MID 16 NOD 0 - $1354
https://www.brownells.com/guns/rifle...o-black-301rd/ MID-LENGTH GAS
SOLGW Patrol SL - $1235
https://xtremegunsandammo.com/shop/r...lgw-patrol-sl/ MID-LENGTH GAS
PSA PA-15 16" NITRIDE A2 MID-LENGTH - $650 -
https://palmettostatearmory.com/psa-...165458949.html
In doing these comparisons, I'd have to say that the SOLGW is the most solid deal, but damn, looking at that PSA at half the price I'm thinking 'what could I spend the left over money on?' and 'Are those other rifles really half-again to twice as good?' This be why I build my own.
Good luck.