Offers from GU - are huge price differences normal?

Hello dear forum members,
we are currently looking for a general contractor for our construction project (semi-detached house, 2 stories + half attic).
We have an offer of 340k, but have already received initial guideline prices from 3 other companies ranging from 410-450k.
Is it really common for offers to differ so enormously?
Is a price of 340 maybe already "cheap"?
Of course, we will look more closely at the construction service descriptions, but which points could justify such huge differences?

Would you also be suspicious if someone offered a fixed price without a time limit?

Best regards

Relatives of ours currently have 3 offers for a semi-detached house with 2 full floors for just under 500k (170sqm + basement) Our offers and those of our friends were in the range of 30k. In this respect, this downward deviation is strange to me.

Of course, we will take a closer look at the construction service descriptions, but which points could justify such enormous differences?

In all of them ;) I wonder, though, how you build. Architect? Because then you specify the construction service description. Otherwise, a comparison will be difficult.

In all ;)

But I wonder how you build. Architect? Because then you specify the construction service description.
Otherwise, a comparison will be difficult.

No, not an architect, several larger companies inquired.
The cheapest was from Helma and a local general contractor, the more expensive were Viebrockhaus and two other local companies..

Regards

No, not an architect, some larger companies inquired. The cheapest was from Helma and a local general contractor, the more expensive ones were Viebrockhaus and two other local companies..

So you get offers for a Dacia, a Passat, a Benz, and a Porsche. Because you told everyone you need a car. Figuratively speaking.

we are currently looking for a general contractor for our construction project (semi-detached house, 2 stories + half attic).

Don’t put yourself through that by requesting half a semi-detached house. Plan together, even if you want to hire different contractors, and even with different construction methods.

We have an offer of 340k, but have received initial guideline prices from 3 other companies ranging from 410-450k. Is it really common for offers to differ so much? Is a price of 340 already considered "cheap"?

All offers – including the most expensive – may have omitted essential items. For laypeople, there is basically only one challenge bigger than the passive tendering process, and you’ve run into that too ("beginner’s luck" a shot - an own goal!): namely also taking on big names at the same time.

have contacted some larger companies.

Is this meant to be an Olympic triathlon? 1. half semi-detached house; 2. without architect; 3. big names