Best to do some research into what features you would like from a detector, and study as many You Tube clips as you can from experienced operators to see if they perform as expected and on how they operate test in the field. The 305 has been discontinued, and neither that detector or the 505 have a dedicated beach mode (I tried the 305 on wet sand, was not the best). That leaves the 705.
My decision on purchasing a vlf for park detecting mainly came down to recovery speed, weight of the detector, user friendliness, requirement for screen backlighting (night detecting), and overall flexibility for various types of sites. Whilst the detectors below may well not personally suit you, it just gives a bit of an idea on how you might go about shopping for a new detector.
Some detectors I considered before purchasing my current Deus included the AT Pro, though the lack of screen backlighting, questionable wet beach performance and the choice of only the international version in Oz had me looking elsewhere. Either way, it would be beyond your budget by $200.
I never really considered the Minelab X-Terra 705 considering I already have an Etrac, and I'm not too keen on the -8 to 48 ID range, much prefer the larger spread of the tradional 0-99 ID range found on most other vlf detectors. That will be purely a personal choice, as many do own a 705 on forum, and have great success and enjoy using them.
The Teknetics G2+ is a tad over budget at $1099 and ticks a lot of boxes, including screen backlighting, ground grab or manual ground balancing, iron volume, VCO tones in discriminate mode, notch mode, and ability to ground balance to salt for beach work. I already have the basic Teknetics G2 model, and it an extremely easy detector to use and set up, lightweight and has good recovery speeds. The G2+ was not considered due to being too similar to my G2, more of an upgrade with additional features vs an advance in overall performance ( my missus mainly uses the G2).
The Fisher F44 did catch my eye and is a pretty feature laden detector for the money, though there has been little or no feedback from owners in Australia to have the confidence for making a purchase on this detector. It is also more regarded as a budget detector, so I wouldn't expect it to perform as well as something around the $1000 mark. Another minus is that it actually states in the F44 manual that it is not suitable for wet sand detecting.
The Red Makro Racer was considered, though being relatively new to the market at the time, I didn't want to outlay money until all the initial bugs were ironed out (as with many new detectors). The other turn off was the lack of a memory to store user settings, something that has been addressed on the Racer 2.
I never considered the Nokta Fors Core purely through personal preference in not having a separate control box mounted under the armrest, much prefer to have ALL controls at my fingertips. All a bit too old fashioned for me, and something I think Nokta need to improve to compete alongside the the more compact Racer detectors.
Lastly, if I hadn't purchased the Deus, or if my budget didn't stretch that far, I would have been seriously considering the soon to be released Makro Racer 2. Being a second genration detector, all the bugs should be well and truly ironed out by now, and the packed list of features on this detector is pretty hard to ignore for a detector around the $1000 mark.
Things that would tick my boxes include screen backlighting, iron volume, ultra fast recovery speeds, dedicated beach mode, notch ability, deep mode, adjustable ID tones, expanded non-ferrous ID range, optional wireless headphones etc etc.
So I guess the gist of my post is to sit down and list all those features and abilities you wish to have in a detector, and use the process of elimination to narrow down choices within your budget. Study the downloadable manuals for each detector, and have a good read on what they can and can't do. Often product flyers conveniently forget to list detector shortcomings, much as I found out on the Fisher F44 for wet sand.