original sentence:
"In your initial application provided we stated with fixed price. The proposal seems to be going well passed that."
This is very badly written and ungrammatical. "passed" is clearly meant to be "past", but otherwise it's not 100% clear to me what meaning is intended, but here's a guess:
"In your initial application provided we stated a fixed price. The proposal seems to be going well past that."
"past" means "beyond" in this instance: it's a preposition, see defn 14 here: http://www.dictionary.com/browse/past
So they're saying that the proposal has gone "beyond the fixed price". In other words, that the proposal is going to cost more money than the fixed amount that was agreed previously.