okay, i would never make an offer over the phone. i would always put it in an offer contract and put subject to inspection subject to partners approval and this way on paper it legally gives you an out.
i recently stopped looking @ homes and this week im gonna put offers in at 65-70% of market value and if they are accepted thats when ill go look at the house. Keep in mind if your offer is accepted on the first try you're asking too much. if no one responds maybe ur asking too little. but whatever the case may be you must figure out a number that you want to get the house for. If you dont get the house for that much then just walk away..
this is what im doing from now on
I see a house i put an offer in they counter offer
lets say the house is 100k
I have preset im not going into the house for more than 70k.
so i offer 65k they respond with 90 i respond wtih 85 lets just say they accept.
then i would do my inspection and everything i found wrong wtih the home i'd negotiate it less and less until i brought it down to 70k or less whichever makees sense when u walk through the home for the first time.
do not get emotional, it's a numbers game and if the numbers dont add up dont go foward with the deal. you wanna make sure u leave contingencies in your contract. they give you a way out if you find something that you extremely dislike. i hope this helps my example prolly sucks but good luck!