Costly Home Buyer Mistakes in California

A Buyer's Story

Marissa and Dan had been renting in North Park for six years. When their landlord raised the rent again, they decided it was finally time to buy. They found a cute three-bedroom in Clairemont online, fell in love with the photos, and called the listing agent directly to see it that same day.

By the time they called me, they had already made two of the ten mistakes in this chapter — and they didn’t even know it.

First, they hadn’t been pre-approved. They just “knew” what they could afford based on a mortgage calculator app, not an actual lender. Second, they called the seller’s agent to see the home, not realizing that agent’s job was to get the seller the best possible price and terms — not to look out for them.

By the time we sat down together, they had already lost two weeks and, more importantly, lost leverage in a multiple-offer situation because the seller’s agent knew they weren’t pre-approved and quietly steered another buyer’s offer ahead of theirs.

Marissa and Dan aren’t unusual. In a market like San Diego County — high prices, tight inventory, fast-moving escrows, and buyers competing against cash offers and investors — small mistakes get expensive fast. This chapter walks through the ten costliest ones I see buyers make, and exactly how to avoid them.

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Mistake #1:
Skipping (or Faking) a Pre-Approval

What it looks like: A buyer gets a “pre-qualification” letter from an online lender in five minutes, or worse, just assumes they’ll qualify, and starts house hunting or writing offers with nothing but a guess backing them up.

Why it happens: Pre-approval feels like paperwork standing between you and the fun part — looking at homes. Buyers want to skip to the exciting stage.

The hidden cost: In San Diego’s competitive price points (especially anything under $1M), sellers and their agents can tell the difference between a real underwritten pre-approval and a five-minute online guess. Offers without real pre-approval get passed over, ignored, or ranked last — costing buyers the homes they actually wanted, sometimes for weeks or months. 

Do this instead: Get a fully underwritten pre-approval — not just pre-qualification — before you ever set foot in a home. This means a lender has actually reviewed your income, credit, assets, and debt, not just asked you questions over the phone.

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Mistake #2:
Calling the Seller's Agent or the Listing Agent to “Just Ask Questions”

What it looks like: A buyer sees a yard sign or a listing online and calls the number, assuming that agent will represent their interests too. Sometimes, a well-meaning friend or relative will tell them this is a savvy thing to do because the Listing Agent will promote your offer over others because he/she will stand to get paid double for representing both sides of the transaction.

Why it happens: It feels efficient - one call, one person, one showing, gain advantage.

The hidden cost: That agent has a legal and financial obligation to get the seller the best price and terms. Any information you share — your budget, your timeline, motivation, your anxiety about the price — can be used against you at the negotiating table, even unintentionally.  Plus, if your offer is accepted and there is ever a conflict between the Buyer and the Seller in the transaction where the agent is forced to take a side, that agent will always choose the seller because if that deal falls apart, they can still sell the home to another buyer.

Do this instead: Choose your own buyer’s agent before you start touring homes, ideally before you even start browsing seriously. A good buyer’s agent can show you any listing, regardless of who represents the seller, and they work only for you.

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Mistake #3:
Choosing an Agent Based on a Referral Fee, Friendship, or a Discount — Not on Skill

What it looks like: A buyer works with their cousin’s friend who “just got their license,” or picks whoever offers to rebate part of their commission, without asking about local market knowledge or negotiating track record.

Why it happens: It feels loyal, low-risk, or like free money.

The hidden cost: A buyer’s agent is your advisor during the single largest financial transaction most people ever make. An inexperienced or overly passive agent can miss red flags in inspections, fail to negotiate repairs or credits, misjudge a fair offer price, or simply not know which San Diego neighborhoods or HOAs have hidden problems. That “savings” on commission can cost tens of thousands in a bad negotiation or a missed defect.

Do this instead: Interview your agent like you would a surgeon. Ask how many transactions they’ve closed in the specific area you’re buying, how they structure offers in multiple-offer situations, and for references from recent buyer clients.