I largely agree with KinTn's list but would change order of priority since a budget is referenced and you have a great general purpose pro coil included (it's still the only one I have for my Safari) so I would push the 6x8 to 4th position.
1) "Garrett or Minelab pin-pointer. ONLY one of those brands. this is a must purchase imo" -Agreed,now that I have the G PP, there's no reason to haul that sub-par crappy automax v4 around anymore ! .
2) Those aftermarket Li packs get a great life between charges (see reviews/customer testimonials on this site), but i use Sony Eneloops (2000 or 2700mAh; but dont mix battery types) + a MAHA charger. i use AAs for a lot of other things around the house. -I use Harbor Freight rechargable 2200mAh & charger
3) Good headphones,or earbuds, currently using Jolly Rogers (but they need detector volume & threshold raised to compensate for headphone's low volume output) as my wireless auvio 283's were crushed,ugh .
4) absolutely get a 6x8. i love my SEF (i use it everywhere except the beach where i use the stock coil) and have never seen a bad review on it.
5) musts: Andy Sabich's book, a Gator or Lesche trowel;
then pick and choose among the following with your remaining funds:
- a larger Predator shovel if you are going relic hunting,-Or...true value 2 foot garden shovel does nicely for under $15.00.
- a good sand scoop (i dont know them well enough to recommend one, tho i prefer a long handeled one) for sand/beach/water hunting,
- tool belt/pouch to put it all on (i use a $15 one from Lowes),
- i use cheap $5 headphones from Big Lots, but you can drop a couple hundred here if you want to
I'm sure I've left something out, but that pretty much covers my hunting.