When you are looking to find MN tankless waterheater dealers you should look out for a few simple things. As usual price is one factor, but not the only factor.
If you live in Minnesota and want to go with a tankless gas water heater, for example, then you really need to be sure that your dealer is competent and experienced with this kind of tankless unit. The US is traditionally the home of the electric, gas or oil tank heater, with the on demand unit only making a real impact fairly recently. So the dealer needs to have had some past history with these units rather than having just started importing them.
There are some very fine on demand water heaters available from overseas manufacturers - these units have been very popular for years in other parts of the world. Many of the biggest sellers in the world are from Japan for example.
Tankless hot water heaters need some expertise in the installation and maintenance so you should be clear with your dealer that this is available with the unit they are suggesting.
The other thing you need to feel content with is that your dealer is at home selling you the right size instant hot water heaters. These are expensive units so it makes sense to get the right size - neither too big or too small. A good dealer will work this out with you.