Hold off for an original M40 or M42 without decal but with liner and chinstrap, purchased from a reputable dealer (or private seller after posting good photos here). You can find these between $300-$400 sometimes. If you buy anything other than an original German helmet, I think you will regret it in the long run!
Not to beat a dead horse, but when it comes to WWII German helmets, accept no substitutes. For another $150 you could buy a nice fire police helmet. It's not a combat helmet, but they're german, not overly faked and are more times than not double decaled helmets. They're a good starting point for a collection. Don't get yourself caught up in SS or camouflage helmets if you're new to this hobby. I've been collecting for about four years and I don't even touch camouflage helmets. They scare the bejesus outta me. Avoid eBay until you have a good working knowledge of helmets because over 90% of German helmets on eBay are total crap. And like the guys said, you will never be happy with a restoration helmet. The return on your investment just won't be there. Take some time to scroll through the steel helmet section and get a feel for the kind of German helmet you like. Helmets are an investment and you want every penny you spend to count. Post any potential buys here before sending any payment. Good luck and welcome!
I know you're eager, as would I, but things like this take time if you want a good deal for a helmet that will leave you feeling satisfied. (as everyone else has already said)
I remember when I was just getting into collecting. I was attracted to the UN helmet, and was thinking of buying a cover and plopping it onto a shell for display purposes.
Fast forward a few hardy years of collecting, research, and using internet search tricks, and I now own a real UN issued PASGT with matching cover. I got it for a steal, and I doubt I'll ever see another UN PASGT for sale any time soon; nor have I seen any sold before.
Point being, hold out for some time. You'll end up regretting spending your money when something really great pops up.