What they actually mean
Usually true, and arguing costs you the room. Most capable buyers could assemble some version of what you sell given enough time — and telling them otherwise insults the competence they just described.
The real comparison is never you versus impossible. It is you versus the version they will actually build, at the pace they will actually build it, alongside everything else they are doing.
The move: Agree, then price the alternative
Concede the capability fully and without hedging. You are not competing with their ability; you are competing with their calendar.
Then ask when they would start, and what comes off the list to make room. Most DIY plans die on that question without you saying anything against them.
If they have genuinely done it before and it worked, this may not be your buyer. Recognising that early is worth more than a won argument.
How it sounds
“Honestly, I could probably put something like this together myself.”
You“You probably could. When would you start — and what drops off the list to make room for it?”
Why it works. It grants the point completely, so there is nothing to defend, and moves the comparison to the one place DIY reliably loses: sequencing against everything else they own.
What loses the deal
“You could try, but it's a lot harder than it looks.”
You have told a competent person they are not competent. Even if you are right, you have now made the purchase an admission, and people do not buy those.
Practise this one
Reading it is not running it. Closer drills you on do it myself against an AI prospect that holds its position and only opens when you earn it — then a coach walks the transcript back and shows you where the call turned. There are 5 do it myself plays in the library, recast around your own offer and price.