EAs overvaluing in London

[WeeLamb]

Just wondering if anyone has had a similar experience...
Have recently had valuations for house in London from three estate agents - two of which were ridiculously high and one lower. The two high ones were adamant they could 'guarantee' buyers at that price on the basis of comparables in the area (that in my opinion we're nothing like my property). I've ended up with 250k between highest and lowest valuation and absolutely no idea who to believe. I can understand EAs would overvalue to get my business but given the sales commission is on the selling price and they just have to wait longer and work harder if they overvalue, I'm not sure why they'd bother. Unless they are genuinely getting the valuation wrong?

There are always agents who will overvalue purely to secure the instruction to sell your property. Then they will suggest you drop the price when nobody bites. Your property will be “stale” buyers will wonder why it sat on the market. But the agent still gets their commission.
Go for the one in the middle or the the agent that comes with a personal recommendation. My advice would be not to the chains beginning with F or K.

The Times did a piece of research about this last week but it's behind the Paywall. It will come as no surprise to anyone that the worst offender begins with an F...