kakakukousyou de nesage ga dekiru ippou de, zikan mo kakaru.

価格交渉 is a compound noun meaning price negotiation or negotiating the price.

It is made of:

• 価格 = price
• 交渉 = negotiation

So together, it refers to the act of discussing price in order to change it, usually to get a better deal.

Here, で shows the means, method, or context.

So 価格交渉で means something like:

• through price negotiation
• by negotiating the price
• in price negotiations

In this sentence, it tells you how the price reduction becomes possible.

So:

• 価格交渉で値下げができる = You can get a price reduction through negotiation

This で is not a destination marker or location marker here. It is more like by means of.

With できる, the thing that is possible is often marked by が, not を.

So:

• 値下げができる = a price reduction can be done / it is possible to lower the price

This is a very common pattern in Japanese:

• 日本語ができる = can do/use Japanese
• 説明ができる = can explain
• 予約ができる = can make a reservation

Even though English might make you expect something like an object, Japanese often treats the thing that is possible as the subject of できる, so が is natural.

It is functioning as a noun here.

値下げ is a suru-noun, which means it can act like:

• a noun: 値下げ = a price reduction
• a verbal expression with する: 値下げする = to lower the price

In this sentence, it is used as a noun inside the pattern N が できる:

• 値下げができる = a price reduction is possible

So although the overall meaning is verbal in English, grammatically 値下げ itself is being treated as a noun.

一方で means on the other hand, while, or at the same time when introducing a contrasting point.

In this sentence:

• 価格交渉で値下げができる一方で、時間もかかる。

the speaker is saying:

• one positive side: you can get the price lowered
• contrasting point: it also takes time

So 一方で sets up a contrast between two sides of the same situation.

A natural English sense is:

• On the one hand, negotiation can lower the price, but on the other hand, it also takes time.

No, it is not really the same usage.

In 価格交渉で, the で shows means/method.

But 一方で is basically a set phrase meaning:

• on the other hand
• while at the same time
• in contrast

So it is better to learn 一方で as one chunk rather than trying to analyze that で in the same way as the earlier one.

Also, you may sometimes see just 一方 without で, depending on style and sentence structure, but 一方で is very common in written and formal Japanese.

も means also, too, or as well.

So:

• 時間がかかる = it takes time
• 時間もかかる = it also takes time

The も adds the idea that this is another consequence besides the earlier point.

So the sentence is not just saying negotiation lowers the price. It is saying:

• you can get a discount
• but also, it takes time

That も helps highlight the second point as an additional fact.

Because かかる is an intransitive verb in this expression.

The standard pattern is:

• 時間がかかる = time is required / it takes time

So 時間 is marked by が.

Compare:

• 時間がかかる = it takes time
• 時間をかける = to spend time on something

These are related but different:

• かかる describes that time is required
• かける describes someone intentionally spending time

In your sentence, the meaning is simply that the process requires time, so 時間がかかる is the natural form.

Because of も, the が is replaced:

• 時間がかかる
• 時間もかかる

Japanese often leaves out the subject or topic when it is clear from context.

In this sentence, the general topic is the act of price negotiation. So Japanese does not need to say something like:

• Price negotiation can lower the price, but it also takes time

Instead, it simply states the two facts:

• 価格交渉で値下げができる
• 時間もかかる

The listener is expected to understand that both statements are about the same situation.

This kind of omission is extremely common in Japanese and is one reason sentences can feel compact compared with English.

Sometimes yes, but the nuance changes.

• けど / けれども = but, though
• でも = but, however
• 一方で = on the other hand, while also

一方で sounds more balanced and analytical. It suggests two sides of the same matter. That makes it a good fit for formal or explanatory writing.

Compare:

• 価格交渉で値下げができるけど、時間もかかる。 = more conversational: You can negotiate the price down, but it also takes time.

• 価格交渉で値下げができる一方で、時間もかかる。 = more structured/formal: Negotiation can reduce the price; on the other hand, it also takes time.

So the sentence you have sounds slightly more formal and objective.

It sounds fairly neutral-to-formal, and especially natural in written explanations, business contexts, or informative speech.

Reasons:

• 価格交渉 is a somewhat formal/business-like expression
• 一方で is more formal and structured than casual けど
• the whole sentence has an explanatory tone

In casual conversation, a speaker might say something simpler, like:

• 値段は交渉すれば下げられるけど、時間もかかるよ。

But the original sentence is very natural in articles, reports, product discussions, or business advice.

A useful way to break it down is:

• 価格交渉で = through price negotiation
• 値下げができる = a price reduction is possible
• 一方で = on the other hand
• 時間もかかる = it also takes time

So the structure is roughly:

[method/context] + [positive result] + 一方で + [contrasting point]

You can think of it as:

• By negotiating the price, a discount is possible; on the other hand, it also takes time.

This kind of structure is common when presenting advantages and disadvantages or two contrasting aspects of one thing.