If you want an A2 style fixed carry handle, and you don't mind the ban-era Colt weirdness, you can frequently find a 20in HBAR or similar configuration for $600-700 on Gunbroker. That's a lot of quality for the price, but again, ban-era Colt weirdness bugs some people. If you don't want to change shit on the wepaon and just want to run mags through it and keep it clean, they're a solid choice.
FN made a fantastic ~$900ish version of the FN15 in a 20in A4 configuration, but it was discontinued. You can find them occasionally for pennies on the dollar on gunbroker. For a complete rifle from FN it is a steal because not a lot of folks ever knew they made such a config, so A4 seeking folks aren't really looking for them.
Presently FN only offers an A4 configuration as the collectors edition with the complete KAC rail system and such and it's much more expensive, as previously mentioned.
Bushmaster (yeah, I know) also makes a fixed carry handle A2 clone variant. An Army buddy of mine got one since that was the 'easy button' for a nostalgic A2 clone for him and he's not super into guns and didn't really know any better. Surprisingly, it has been accurate and trouble free for him. Upon inspection it's actually put together OK aside from poor gas key staking and a slightly too-long gas tube, both of which were easy enough to fix. Feature wise it was spot on for an A2 except the 1/9 HBAR profile barrel, the lack of coating on the sling loops, and the plastic buttstock trap door. At $700-750ish street price out the door, you could do worse.
The PSA A2 clones bug me because they use an F marked FSB, which is slightly shorter than the FSB that's correct for a fixed carry handle. This means you need to run the front sight post up much further to zero and for me it kind of wrecks the immersion/authenticity since it's hard to un-see anything on the front sight and actually still use the rifle. Obviously for an A4 or other flattop setup the F marked FSB is the correct thing. Otherwise it's a PSA product and as long as you're willing to fix the little things that were a little off when they put it together, it should be fine.
CMMG makes/made an A1 length fixed stock with A2 features, which is a nice combo if you want something a little shorter than the A2's pole vault but don't want to mess about with adjustable stocks or carbine stocks, or a vintage A1 stock that's $$$ these days because of retro builders.
Personally, I really like a 20in rifle with a 6 or 7 position carbine extension and an H6-ish buffer. But I'm 5ft 9in and in full battle rattle I find the A2 stock to be a pain in the ass, especially getting in and out of confined spaces. The M4 buttstock makes a big difference in that regard. But the needs for a 'working gun' in that regard differ considerably from a field rifle being used as Mr. Malamute described.
That is a very good price for an LGS. Most rack prices I've seen for a new AR15A4 are in the $1200-1250 range.