I'm getting offered a new unused AXE Hammer by Busse sold by Axelson Tactical on a firearms trade.  I don't own very many newer knives and the ones I do have I haven't paid over $50 for.  I was just curious on the resale value of this knife incase I would get it and decide I didn't want to keep it?  I see they are about $400 if they're in stock.

$400 seems reasonable.  Give or take it should stay there or increase slightly if you don't use it.

Is it INFI or sr101?

Both are superb steels, but collectors who should be your target buyers, have a strong preference for INFI.

Edit:  I went and looked, it is INFI.  

$400 isn't a screaming deal, but its within reason.   And it seems to be in stock now instead of having to wait forever.

All Axe Hammers are INFI.

The Axe Hammer came in two flavors ...

Combat Grade which had a sage color coated blade.
LE which had a satin and serial numbered blade.

Both were offered for sale with an added cost sheath (made by Dave Brown).

$400 is a good deal for a new Combat Grade if it has a sheath.  It would a SCREAMING deal for a LE.

I sold one of my CG for $475 recently (it had the sheath with it).

As a related side ... the Axe Hammer is a great knife.  If you're accustom to $50 knives .... you may want to consider keeping the Busse.  I'd rather have one $400 Busse than one hundred $50 knives.  

Busse knives actually hold or increase in value.  Most other "brands" are commodities that decrease in value.

I've had five or six Axe Hammers over the years (CG and LE).  They really are outstanding (thin blade unlike most Busse products).