Tree Climbing Beginner Gear

What is the minimum amount of gear I need to safely ascend trees using the SRT technique? My budget is around $500, is that going to cut it? I've been eyeing arborist specific gear so far, but wondering if climbing gear can be adapted? I'm expecting I'll need 50m of rope, harness, helmet, rope devices, lanyards/slings? More info: 5'10", 180lbs, male, I'm expecting to climb recreationally in the Upper Peninsula Forests.

Disclaimer, I am not an arborist. This is the bare minimum I’ve used for SRT in the past:

Harness, helmet, 50 m static rope, long cordelette for anchor, couple locking biners, grigri, one set of aiders, slingshot. 

You can use climbing gear for recreational tree climbing for sure, especially for SRT. A climbing rope+Grigri and hand/ascender + foot loop can get you up and down (although not as efficiently as other actual “rope-walking” arborist setups). Make sure you get a throwline+throwbag so you can set your rope easily from the ground in many different trees.

Bare minimum would be just the rope, choke one end around branch. Make a harness from two loop Bowline on the other end, leave a long tail to act as harness belt and to tie a friction hitch on itself. A single foot lock on the rope replaces the foot ascender, advance hitch by pushing up.  To descend convert from SRT to a moving rope system, hitch will slide down easily.

But Tamiban’s list would be more comfortable, don’t see the need for a gri gri or rig if you have a belay tube, and a hitch could replace the Croll.  HTP is nice for having very little stretch, but hardens up like a cable with use, a semi static stays flexible and unless you take up tree work as a profession, I doubt the difference in stretch will make a difference.

If climbing Pine trees be ready for the sap that will coat your rope and gear, I have separate harnesses and gear for the two types of trees for that reason.