I'm afraid the offer is unacceptable.
The offer is not workable.
The offer is given without engagement.
It is difficult to quote without full details.
Buyers do not welcome offers made at wide intervals.
We cannot make any headway with your offer.
Please renew your offer for two days further.
Please renew your offer on the same terms and conditions.
We regret we have to decline your offer.
The offer is withdrawn.
We prefer to withhold offers for a time.
Buyers are worried at the lack of offer.
Words and Phrases
to extend an offer 延长报盘
to renew an offer 或 to reinstate an offer 恢复报盘
to withdraw an offer 撤回报盘
to decline an offer 或 to turn down an offer 谢绝报盘
at wide intervals 间隔时间太长
make headway 有进展
be worried at sth. 对...苦恼