Negatives Flatbed Adapter Whats The Best Way To Scan Film Negatives?

Whats the best way to scan film negatives? - negatives flatbed adapter

I have hundreds of old negatives from the pre-digital age. I want an inexpensive scanning. COOLSCAN lakes are expensive. Seller would like to digitize more than 50cents per shot (translated from this page). Has anyone had experience with HP flatbed scanner regularly (eg ScanJet 4370), with its negative adapter? It is good quality?