$300 product, 0.5% conversion, 30k+ impressions – listing looks fine on paper. What's actually wrong?

Quick reality check on your numbers vs. category benchmarks.
Average conversion for kitchen on SP ads is 8-12%. You're at 0.5%. Average CTR is 0.3-0.5%. You're at 0.1%. Something is fundamentally misaligned.
Most likely: keyword-product mismatch.
You said traffic is "relevant" but 70 clicks on core keywords with zero orders says otherwise. Are you sure the keywords you're targeting match the actual use case for your slightly larger product?
Example: If you're selling a "countertop compost bin" but targeting "kitchen trash can" – technically relevant, but wrong intent.
Fix: Pull your Search Term Report. See what customers actually searched when they clicked your ads. If the search terms don't match your product's primary use case, that's your answer. Pause everything and rebuild keywords based on actual converting search terms, not what you think should work.
Also – 0.1% CTR at 300k impressions usually means your main image isn't winning in the SERP. Even if you think it's fine, test it. Compare against top 10 competitors. What are they doing that you're not? Better lighting? Angled shot? Lifestyle context? Copy that. Don't reinvent. Steal what works.

I'm going to say something you won't want to hear: maybe this product just isn't going to work at this price point.
You have 30 reviews at 4.8 stars. That's genuinely good. But if you're 45 days in with 0.5% conversion, the market is telling you something.
Two possibilities:

1. The slightly larger capacity isn't valued by buyers. Sometimes "different" isn't better. It's just different. If the competitor's size is the industry standard, going bigger might actually hurt you – people's cabinets are sized for standard dimensions.
2. The category is too saturated for a me-too product. Even with upgrades, if the top brand has 5000+ reviews and a loyal following, you might need a more significant differentiator to pull customers away.

What I'd do before giving up:
Run a small external traffic test. Send 500-1000 clicks from Facebook or Google to the listing. See if conversion improves. External traffic signals carry more weight in A10, and it'll tell you if the problem is Amazon's algorithm or the product itself.
If external traffic converts well but Amazon traffic doesn't, you have an Amazon-specific ranking problem. If neither converts, the product/price is the issue.

Let me be direct: you're spending $300/day on a product with no conversion history. That's the mistake.
Before you scale spend, you need to prove the product can convert at all.
Here's what I'd do starting tomorrow:
Week 1-2 – Find the angle

• Cut daily spend to $50
• Run only exact match on 5-10 long-tail keywords that describe specific use cases
• No broad, no auto, no competitor ASINs
• Goal: Find 2-3 search terms where conversion >5%

Week 3-4 – Double down

• Take the winning keywords, increase bids for Top of Search placement
• Add Sponsored Brand ads on the same terms
• Keep budget at $100/day, focused only on winners

Week 5-6 – Scale

• Once you have consistent daily orders (5+), start adding placement modifiers
• Slowly increase budget to $150-200/day
• Add Product Page campaigns at low bids for presence

Don't scale empty spend. Prove the model at small scale first. Right now you're betting $300/day on a hypothesis that hasn't been validated.

One thing nobody's mentioned: your competitor is VC.
VC accounts play by different rules. They have preferential placement, lower CPCs, and access to programs normal sellers don't. You're not competing on a level field.
What this means for you:

• Don't try to beat them on the exact same keywords. They'll outspend and outrank you every time.
• Find the gaps they're missing. Check their 1-3 star reviews. What are buyers complaining about? Size? Assembly? Durability? Solve those problems and put it in your copy.
• Target comparison keywords ("X vs Y") where shoppers are actively deciding between options. That's where you can win on features, not just price.

Also – if they're VC with thousands of reviews, they're probably not watching their listing closely. That means you can win on listing quality. Better images. Better A+. Better video. Out-execute them where they're asleep.

I had a $220 product with almost identical numbers. 0.6% conversion, 250k impressions, nothing working.
What finally moved the needle:
I stopped trying to force it and started feeding it.
Month 1: Dropped price to $179 (breakeven), ran heavy Top of Search PPC. Took the loss. Goal was sales velocity, not profit. Got 15-20 units/week moving.
Month 2: Raised price to $199, added 10% coupon. Sales dipped but held above 12 units/week.
Month 3: Raised price to $219, coupon to 5%. Sales stabilized at 10 units/week.
Month 4: Raised price to $239, no coupon. Sales at 8 units/week but now profitable.
Month 5-6: Slowly increased price to $259, maintained 6-8 units/week.
Total time: 6 months. Ended at a higher price than competitor, with consistent sales.
Key insight: You can't skip the "feed it" phase. You need to create sales history at a lower price point to build rank and reviews, then slowly walk price up. The algorithm needs to see sustained velocity before it trusts you at a premium.