"The lowest offer..."
It is reckless to pay too much but it's even worse to pay too little.
When you pay too much it's true you may lose a little money but this is where it ends.
When you pay too little you risk losing everything because what you have purchased is not able to do the job you purchased it for.
Common business law makes it impossible to pay little and get lots: this cannot happen.
If you deal with the lowest offer you should remember to build up a certain reserve fund to cover the risk you are taking.
But if you can do this then you certainly also have enough money to buy something better.