I do not like the back and forward issue. I like to kill it all in one swoop. So, I have my buyers per-approved/qualified and I look in that pricing range. If the price goes up, oh well, because I believe when the price goes up, at that time, it's over the amount that my buyer have been approved for. Majority of the time, if we (the buyer) add more to the offer, it's in the pre-approved range.

My question, what's the point of changing letter and amount when the lender have approved them for a certain amount?

Lovestjac,
What the point is: if your buyer is approved for a million and is trying to buy a 50,000 house do you think he is going to get it for less than the 50,000? Even though the buyer may not be willing to go that high, the seller is going to look at that and want the full 50,000.

When I write a pre-approval letter, I usually state the buyer "is qualified for at least $XXX"