Did they diagnose, or just look at the puddle?
This is the question that separates a real quote from a guess. Standing water is a symptom. The fix depends entirely on whether that water is surface runoff, subsurface flow moving under the turf, roof discharge with nowhere to go, or a grade that sends everything back toward the house.
Those four causes have four different solutions, and a contractor who quoted from a photo or a five-minute walk has picked one at random.
Ask directly where the water is coming from and where their system discharges to. If the answer is vague on either end, the number attached to it does not mean much.
Where does the water actually go?
A drainage system is only as good as its outlet. Collecting water efficiently and then releasing it ten feet away, or somewhere it flows straight back, solves nothing.
A quote should say where the discharge point is and why that point works. Elevation matters, because water does not run uphill, and a discharge that sits higher than the drain will hold water in the pipe.
It should also be a legal and neighbourly outlet. Solving your drainage by routing it onto the property next door creates a different problem.
Compare what is actually in the trench
This is where cheap bids get cheap, and it is invisible the day the job is finished.
Ask about pipe type and diameter, whether the gravel is washed and correctly sized, and whether filter fabric is included. A French drain without fabric will silt up, and the timeline on that is a couple of seasons, not a couple of decades.
Ask about fall. A drain line needs consistent slope along its run to move water. A trench dug flat will hold water and become an underground puddle. If nobody mentions fall, they may not have planned for it.
What restoration is included?
Drainage work means excavation, and excavation means turf and beds get disturbed. Whether restoration is in the price is a common gap between two quotes that otherwise look similar.
Ask whether sod replacement, bed repair, and haul-off of spoil are included, or whether you will be handed a yard full of trenches and dirt piles to sort out yourself.
That difference alone can explain a meaningful part of a price gap.
Credentials and warranty
Drainage is unregulated in a way irrigation is not, so anybody with a trencher can sell it. Certification is a reasonable proxy for whether the person sizing your system knows how to size a system. John is NDS drainage certified.
Ask what the warranty covers and for how long, specifically whether it covers labour or only materials. A materials-only warranty on a system that failed because of design is not worth much.
And ask whether the same company handles the irrigation and landscaping that the drainage work will disturb. If not, you are coordinating between trades and absorbing the gaps between them yourself.
The cheapest bid is sometimes correct
None of this means the low bid is wrong. Sometimes a property genuinely needs a simple downspout extension and one contractor correctly scoped a small job while another oversold a system.
The point is to compare like for like. Once you know the diagnosis, the discharge point, the materials, the restoration, and the warranty for each quote, the numbers usually make sense.
If a quote will not give you those five things in writing, the price is not the risk. The rework is.