הצעת המחיר המפורטת כוללת מקדמה ותשלום לפי התקדמות.

This is a very common Hebrew structure called construct state (סמיכות).

• הצעה = proposal / offer
• מחיר = price

When Hebrew puts them together as הצעת מחיר, the meaning becomes something like:

• a price proposal
• a price quote
• a quotation

So הצעת המחיר means the price quote or the quotation.

Because the noun is in the construct state.

The basic form is:

• הצעה = proposal

But when it is followed by another noun in a construct chain, it changes to:

• הצעת = proposal of ...

So:

• הצעה = a proposal
• הצעת מחיר = a price proposal / price quote

This change is very common with feminine nouns ending in ־ה: they often become ־ת in the construct form.

In a construct chain, definiteness is usually shown on the last noun, and that makes the whole chain definite.

So:

• הצעת מחיר = a price quote
• הצעת המחיר = the price quote

Even though only מחיר has ה־, the entire phrase is understood as definite.

That is why Hebrew does not normally say ההצעת המחיר.

Because it agrees with the head noun הצעה, which is feminine singular.

• הצעה = feminine singular
• therefore מפורטת must also be feminine singular

So:

• הצעת המחיר המפורטת = the detailed price quote

Even though מחיר is masculine, the adjective describes the whole phrase whose main noun is הצעה.

In Hebrew, adjectives usually come after the noun they describe.

So instead of English-style the detailed quote, Hebrew says:

• הצעת המחיר המפורטת
• literally: the price quote detailed

This is normal Hebrew word order.

Also, when an adjective describes a construct phrase, it usually comes after the whole phrase, not in the middle of it.

כוללת is the present tense form of the verb לכלול = to include.

Here it is:

• feminine singular present

It agrees with the subject:

• הצעת המחיר המפורטת = feminine singular

So:

• הצעת המחיר המפורטת כוללת ...
• The detailed price quote includes ...

Compare:

• החוזה כולל = the contract includes (masculine singular)
• ההצעה כוללת = the proposal includes (feminine singular)

Hebrew does not have an indefinite article like English a/an.

So:

• מקדמה can mean a down payment / an advance
• תשלום can mean a payment

If a noun does not have ה־, it is often indefinite, depending on context.

That is why:

• כוללת מקדמה ותשלום = includes a down payment and payment...

They are related, but not the same.

• מקדמה = an advance payment, deposit, or down payment
• תשלום = payment

So the sentence suggests two parts:

1. an initial payment up front
2. additional payment based on progress

In business or contract language, מקדמה is a very common word for money paid before the work is finished.

Literally, לפי means according to or based on, and התקדמות means progress.

So:

• לפי התקדמות = according to progress
• more naturally in English: based on progress or as the work progresses

In this kind of business context, it often means payment is made in stages, depending on how much of the work has been completed.

Without ה־, the phrase sounds more general or abstract:

• לפי התקדמות = according to progress / based on progress

If you say:

• לפי ההתקדמות

that sounds more like according to the progress, referring to a specific known progress status.

Both can exist, but the version without ה־ is very natural in formal or business wording.

The ו־ at the beginning simply means and.

So:

• תשלום = payment
• ותשלום = and payment

In Hebrew, conjunctions like ו־ are attached directly to the following word.

So the phrase:

• מקדמה ותשלום לפי התקדמות

means:

• a down payment and payment according to progress

Yes, it sounds fairly formal and business-like.

Words and phrases like:

• הצעת מחיר
• מפורטת
• מקדמה
• לפי התקדמות

are very common in quotations, contracts, invoices, and project proposals.

A more casual spoken sentence might use simpler wording, but this version sounds natural in professional writing.