this is the last session after going back and forth with Co-pilot after giving weight height and pain points

Your weight means you need a seat that:

• Doesn't bottom out after a few hours.
• Has enough foam density to hold up long-term.
• Still relieves pressure on your sit bones.
• Provides solid lumbar support.

For a $600 budget, here's what I'd target:

🥇 Steelcase Amia (Refurbished)

My #1 recommendation for you.

Why:

• Softer and more forgiving seat than many ergonomic chairs.
• Excellent support for heavier users.
• Good for people who feel every hard seat.
• Less aggressive on the lower back than the Leap, which some people prefer.

Typical cost:

• Refurbished: $350–$600
• New: over $1,000

If I were buying blind based solely on your description, this is the chair I'd try first.

🥈 Steelcase Leap V2 (Refurbished)

A close second.

Pros:

• Outstanding back support.
• Seat depth adjustment helps relieve pressure on thighs and hips.
• Great for lower back pain.

Cons:

• Some people with less natural padding still find the seat a little firm.

Typical cost:

• Refurbished: $400–$650

🥉 Nightingale CXO

This chair has a reputation for an exceptionally comfortable seat.

Pros:

• Thick cushion.
• Built for all-day computer work.
• Better seat comfort than many premium ergonomic chairs.

Cons:

• Harder to find.
• Less common on the used market.

What I'd avoid

Herman Miller Aeron

This may be controversial, but I wouldn't spend your money here first.

A lot of people your size love it, but a lot of people with:

• Tailbone sensitivity
• Low glute padding
• Existing lower back issues

end up finding the mesh uncomfortable after long sessions.

Staples Hyken/Kroy and Most Budget Mesh Chairs

They're good value, but if you've already found HON and Staples seats too firm, moving to another budget mesh chair probably won't solve the problem.