I have a chance at one for a hair under $700. Are these a good starter 308 AR?
Or should I stay away?  I'm looking at it for a 200 yard and under deer rifle.

Yes, its a good price. Probably a slick side upper with a short gas system and a high rail...? Not wild about it but it is a good rifle and will suit your purposes.

No. It has a fwd assist. Regular height upper.

Good Starter mine runs fine free floated barrel.

 plan to replace the gas block with a adjustable one much smoother and i hear the aluminium ones like to come loose

Not too bad of a rifle... I got the Sportical which is the same as oracle but without forward assist.

I've had one for a month and a half. I've had it out every weekend trying to find a handload it likes. First thing to do is get a better trigger. Most of the Oracle's come with a 7-8 pound trigger, which wouldn't be so bad if it was smooth and crisp. Mine, and a friend's 5.56mm Oracle, felt like there was a bucket of sand in the FCG and multiple stages to go through. I got mine to 5 1/2 pounds and much smoother, but it still feels like it has 3 stages of take up. It will have to do until I can get an aftermarket. I prefer a single stage trigger, and keep it at least 4 1/2 pound pull for reliabilty. I have heard good things about the new Velocity triggers.
Next up will be a Free Float handguard, probably an Apex as they are simple and light. And toning down the excessive gas. Adjustable gas block, and better buffer and spring. I've already put a Troy Medieval Muzzle brake on it, maybe helps a little.
I didn't like the factory stock or A2 grip and replaced with a Magpul ACS and Moe+ grip. I am getting 5 shot  groups at 100 yards that are around 1.5 inch with handloads consisting  of Hornady 150 grain FMJ and SST's. I was trying to use up several pounds of W748 powder I had, got some IMR-4895 the other day, it and Varget have done best in my M700 bolt gun. The W748 hasn't been the best in the bolt gun either.I figured no use spending more money trying Match bullets in the Oracle until I get a better scope for it, free float the forend, tone down the gas and get a better trigger.
Certainly acceptable accuracy for an entry level $700 carbine with no frills. If it won't get sub Moa after I finish upgrades, I might consider a better barrel , probably an 18" mid length gas system.

It is exactly what you are looking for, an entry level budget rifle. At that cost, you can afford to upgrade it over time as you learn what you want and what it likes, and still not have a fortune tied up. Or, you can afford to shoot it a while, decide exactly what you want, sell it, and buy something else.

Why not a bolt gun if you are trying to keep the price that low.

Its a nice rifle for getting into a AR10. Not high priced like others and if you find out you don't like it, not allot invested. I have one now. Upgraded the trigger to a timney, changed the hand guard to a midwest industries quad rail, and currently has a nikon M308 scope on it. Loves 168 gr A-Max (i reload) and shoot hornady 150 gr fmj for plinking/SHTF. Nice semi for the money. You can always upgrade the barrel to a better one down the road, which is my plan. Bolt will be cheaper and lighter but its not a semi auto. Go for it if you want a semi. Plenty of upgrade options down the road for it. Plus, its a fucking blast to rapid fire 20 rounds real quick. Try that with a bolt gun.