inventory and sales per month?

so i’ve been looking around stores for awhile doing RA and i’ve found a few profitable items but i can’t help but notice when im using seller amp and looking at what people have in stock/offers everyone had low inventory and lower prices to sell, even lower than amazon but i also found the item around the same price as them to sell for but there was 10 sellers with like less than 5 items of inventory in stock and the product was selling 1000+ a month while amazon was selling the product overpriced but with 500 in stock so im just seeing what my perspective should be on the offers tab for seller amp or if i should go in there buy the stuff and sell it for profit and stop overthinking