I can answer that one.
If I buy cheap untreated seeds I get far less germination, rot and insect damage thus a lower crop.
Now you don't have to spend top money to buy a great scale but you certainly do not want a cheap inaccurate one either.
I don't use a top dollar one but it isn't the cheapest either. I like my Lyman 1000XP. I have had it for a few years and I think they run around $130 today.
Brian Enos sales a cheaper one on his site for around $75 that people really like. It even has something like a 20 year warranty. He also has a top German made scale for around $135 with a life time warranty.
BTW the Lyman has been tack on since the day I bought mine and works really well with either batteries or the AC adapter.