bro youve opened up a can of worms here... 800? you can get so many, almost consider that too many options lol,
time for my 2 cents.
my favorite is my
element ecto, (the only element i recomend typically) twas my first truck and has taken more abuse than any average 4 crawlers combined and still rips the lines. lots of aftermarket upgrades available. ( i recently built a comp fox, really similar but more capable)
scx10 - awesome trucks amazing aftermarket support, my sons basecamp is one of the toughest most durable trucks we have.
redcat- the ascent and apex are amazing, the others not so much, not the worst but their gonna leave you wanting for more ( id suggest getting a redcat after you have others, as in MY PERSONAL EXPERIENCE they arent the most capable other than the ascent platform.
vanquish- man their stuff is sweet, its the brand snobs brand of choice, its the priciest, it shows others you're "more serious about crawling than they are" but its also one of the top brands, not just because of that but because they are really well designed.
ANY of these will fall under the 800 mark, leaving you room for : aluminum beadlocks, brass, tires wheels, shocks, possibly a better servo or motor (hobbywing quickrun fusion pro for the win) then you're gonna want a new body, maybe decide you want a tow rig attatchment, in my experience most parts online are geared to the scx10 platform, everyone makes stuff for that.
an example of aftermarket availability: go try to find a tow boom, the one i got was for the scx10 ii, but its on my redcat ascent.... its MOSTLY compatible, but try to find one specifically for the
trx4 platform, now it just got harder... they all have brass upgrades across the market, but when you start looking for specifics thats where the differences pop up, the
trx4 is wider than the scx10 so my boom while it would fit the scx and the redcat wouldnt fit the
trx4, even tho it says "Compatible Brand: Any Brand" little things like that lead to learning a new aspect of the hobby,
but say you want a light kit? universal, theyll about go on any vehicle, super interchangeable. but you want a steel bumper? now you're looking fr a brand specific item if you want proper fitment.
sometimes you gotta try em all, their like danged ol pokemans man lol, everyone has an opinion on the best, but to me the best is whatever I'm driving or building lol,
i ramble a lot.
if you go with an element, axial, redcat or traxxas, you're gonna dig it, but its a gateway truck you gotta understand this above all else. its not likely to be your last, so dont stress it as much,
also consider your terrain!! super important!! if you're driving thru the woods with lots of leaf litter and branches, well a lcg (low center gravity) truck wouldnt be as ideal as say a hightrail or something similar, my ecto is a belly dragger, super low cg, fll droop shocks, made to stay low and planted as i crest rocks. i get stuck in spots my sons basecamp just rips right over cause of those additional 2 inches of clearance he has, he glides right over the top of stuff thats getting in my way. BUUUUT when we approach steep angles the ecto shines because its generally more planted, sidehilling? the ecto trucks on while the basecamp (having a higher cg) has a harder time with the body and higher cg working to roll the truck sideways.
all of this can be adjusted to a point, but may be worth considering.
the redcat and basecamp both trail better than my ecto, but my ecto rock crawls better than them both. its a fun competition between the trucks to see which is the BEST that day lol.
look forward to seeing what you get bro
Totally agree with picking a body style you like and go from there. With your budget, you really can not go wrong with any of the above mentioned rigs. Sometimes it just boils down to looks with your first rig. 
