Why Two Similar Japanese Cars Can Have Drastically Different Auction Values

[abdulsamad]

I've been looking at a few options to buy cars from Japan and something has been puzzling me.
I recently compared two very similar cars at auction, both Toyota Estimas from around the same year, similar mileage, and on paper they looked almost identical. Yet one sold for what seemed like a bargain, while the other went for significantly more money.
As someone based in the UK, I'm trying to keep my total budget under £8k landed and registered, so these differences can make a big impact once shipping, VAT, insurance, and DVLA registration costs are added in.
What am I missing when it comes to auction values?
A few things I've been wondering about:

• How much does auction grade really affect the final price?
• Do service records or previous repairs make that much difference?
• Are certain colours or trim levels more desirable in Japan?
• Can minor notes on the auction sheet dramatically change bidding?

I've also noticed this when looking at performance models and hybrids. Sometimes two cars that appear almost the same end up thousands apart in auction price.
For those who regularly buy cars from Japan or import them into the UK, what factors do you check first when assessing whether an auction result was fair value?
I'm sure there's something in the auction data that experienced importers spot straight away, but as a relative newcomer I'm struggling to see it.