Pre Approval Number, Everyone Sees?

[Michael P.]

Hey Folks,
I have 2 properties I am interested in, 1 is on the market, 1 off market, same seller. 1 is listed 45k, I am coming in with 35k offer.  Second asking 70, I am coming in at 55, probably expecting a counter.  Been on the phone with BOA, local credit union, J Went for quotes on 10yr, 12yr fix balloon.  

My question is, if I am providing my realtor with a pre approval, what amount should it be? Exact amount of the initial offer? A little more?  I am confused on If i am pre approved at 120, but going in at 90 lets say, the seller knows I can go higher, this seems to me as an issue in negotiations.

Please help.