This PoE 3.18 Sentinel Seismic Trap Saboteur is a good league starter build with low budget and HCSSF available.

 

Skill Tree

Bandit: Kill All

Passive Tree & PoB

Path of Building Link: https://pastebin.com/T3dZCyfp

 

Gems Setup

Seismic Trap - Increased Critical Strikes - Trap and Mine Damage - Advanced Traps - Increased Critical Damage - Brutality

Gloves: Exsanguinate - Cluster Traps - Chain - Charged Traps (Use Trap support until you get "Socketed Gems are Supported by Level # Trap" mod.)

The Devouring Diadem: War Banner / Herald of Purity / Pride / Summon Skitterbots

Vaal Grace - Bear Trap - Increased Duration - Steelskin

Whirling Blades - Faster Attacks - Fortify

Summon Stone Golem / Flame Dash - Second Wind

Gear Setup

Quality does not increase Defences
Grants +1 to Maximum Life per 2% Quality
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20% increased Evasion and Energy Shield
Regenerate 26 Life per second
+37 to maximum Mana
+10% to Cold Resistance
9% increased Stun and Block Recovery
+1.43% to Spell Critical Strike Chance
+84 to maximum Life

Armour: Sample

Weapon: Cold Iron Point

Helmet: The Devouring Diadem

Gloves: Socketed Gems are Supported by Level 22 Trap

Belt: #% increased Trap Throwing Speed

Ring: Curse Enemies with Vulnerability on Hit, with #% increased Effect

Amulet: +1 to Level of all Physical Skill Gems, Critical Strike Multiplier. Allocates Arcane Potency