Die Mindestlaufzeit beträgt zwei Jahre, wohingegen die Anschlussgebühr zwanzig Euro beträgt.

Not exactly. Wohingegen introduces a contrast, and it is closer to whereas or while, by contrast than to simple but.

So the sentence is setting two facts against each other in a fairly formal, written style:

• one fact about the minimum term
• one fact about the fee

Compared with aber, wohingegen sounds more formal and more typical of contracts, product descriptions, and written comparisons.

Because the two clauses are different types:

• Die Mindestlaufzeit beträgt zwei Jahre is a main clause, so the conjugated verb goes in second position.
• wohingegen die Anschlussgebühr zwanzig Euro beträgt is a subordinate clause, introduced by wohingegen, so the conjugated verb goes to the end.

So:

• main clause: Die Mindestlaufzeit | beträgt | zwei Jahre
• subordinate clause: wohingegen | die Anschlussgebühr zwanzig Euro | beträgt

This is a very common German pattern.

Because wohingegen introduces a subordinate clause, and German normally uses a comma before subordinate clauses.

So the comma is not optional here in standard written German:

• Die Mindestlaufzeit beträgt zwei Jahre, wohingegen ...

This is one of the big differences from English punctuation.

In this sentence, repeating beträgt is the normal full form because each clause needs its own finite verb.

• Die Mindestlaufzeit beträgt zwei Jahre
• die Anschlussgebühr beträgt zwanzig Euro

German can sometimes omit repeated material in shorter, more elliptical styles, but in a standard, formal sentence like this, repeating the verb is the clearest and most natural choice.

It also helps because the two things being measured are different:

• a duration
• an amount of money

They are in the accusative, because betragen is a verb that takes a direct object.

So the structure is basically:

• Die Mindestlaufzeit = subject
• beträgt
• zwei Jahre = accusative object

and

• die Anschlussgebühr = subject
• beträgt
• zwanzig Euro = accusative object

In this sentence, the case is not very visible because:

• Jahre looks the same in nominative and accusative plural
• Euro usually does not change form here either

You can see the accusative more clearly with a masculine singular noun:

• Der Preis beträgt einen Euro.

That einen shows the accusative clearly.

Because after beträgt, you need the accusative form, not dative.

• zwei Jahre = correct here

You often see zwei Jahren after certain prepositions, especially:

• seit zwei Jahren = for two years / for the last two years
• in zwei Jahren = in two years

Those prepositions require different cases, which is why the form changes there. But with betragen, you do not use Jahren.

They are compound nouns, which German uses all the time.

Mindestlaufzeit

This can be broken down as:

• Mindest- = minimum
• Laufzeit = duration, term, period of validity

So Mindestlaufzeit means the minimum contract term or minimum duration.

Anschlussgebühr

This can be broken down as:

• Anschluss = connection / hookup / activation
• Gebühr = fee

So Anschlussgebühr is a connection fee, setup fee, or activation fee, depending on context.

A very useful habit in German is to look for the last part of the compound first. That usually tells you the basic category of the word.

Yes, both are feminine.

A key rule for German compounds is:

The grammatical gender of a compound is determined by the last element.

So:

• die Laufzeit → therefore die Mindestlaufzeit
• die Gebühr → therefore die Anschlussgebühr

This is very helpful when learning vocabulary. Even if a compound is long, the last part usually tells you the gender.

Because with plain numbers, German usually just uses:

• zwei Jahre
• zwanzig Euro

without an article.

That is normal for amounts, prices, durations, distances, and similar measurements.

If you added an article, it would usually make the phrase more specific:

• die zwei Jahre = those two years
• die zwanzig Euro = those twenty euros

But here the sentence is simply stating values, so no article is needed.

Betragen is a very common formal verb for stating an amount, measurement, or duration.

It works well for things like:

• prices
• fees
• distances
• percentages
• time spans

So both of these are natural:

• Die Mindestlaufzeit beträgt zwei Jahre.
• Die Gebühr beträgt zwanzig Euro.

Compared with sein

You might sometimes hear something like:

• Die Mindestlaufzeit ist zwei Jahre.

People may understand it, but beträgt is more idiomatic and more formal in this kind of context.

Compared with kosten

Kosten is good for something that has a price:

• Die Anschlussgebühr kostet zwanzig Euro.

But you would not normally use kosten for the contract duration:

• not: Die Mindestlaufzeit kostet zwei Jahre

So betragen neatly works for both parts of the sentence.

Because they are nouns, and in German all nouns are capitalized.

That includes:

• abstract nouns
• compound nouns
• units and currencies when they are nouns

So:

• die Mindestlaufzeit
• die Anschlussgebühr
• zwei Jahre
• zwanzig Euro

This is one of the most visible features of written German.

Yes. You could say:

Wohingegen die Anschlussgebühr zwanzig Euro beträgt, beträgt die Mindestlaufzeit zwei Jahre.

That is grammatically possible, but it sounds less natural in many contexts because the original order is clearer and more straightforward.

If a subordinate clause comes first in German, the main clause still follows the verb-second rule, which means the verb comes immediately after the whole first clause:

• Wohingegen ... beträgt, beträgt die Mindestlaufzeit zwei Jahre.

So the main clause subject does not come directly after the comma; the verb does. This is a classic German word-order pattern.