If the £800 5* is for a solo traveller, then it's not surprising as it's going to more than half the price for two people travelling. Plus if it's £200 per night and £200 for the flight incl luggage and transfer, it's not 'extortionate' at all, it's pretty much what you'd expect.
But as for the OP, prices could equally go up or down depending on availability, which could obviously reduce nearer the time. I think for the lowest price, I would look to go in early July, before the school holidays start in England and Wales and be as flexible as possible on dates, destination and which hotel etc.
We've booked under a week before and while it's not cheap cheap, we've always been able something suitable. For a few days in the sun, we generally go on jet2holidays packages because they're usually comparable in price to booking separately and at this time of year, for various reasons, we're generally looking for an easy no stress few days in the sun, that doesn't need too much thought or research, so a package meets this need.
I'd have a look now and if there seems to be plenty of choice, perhaps leave it until you're under 2 weeks before departure date to see if there's any last minute discounts, but if looks like there's not a lot left, or if you spot something you really want, I'd probably bite the bullet and book now as I can't see the price going down by loads at this late stage.