Big 5 is a nice chain sporting goods store. They specialize in on-sale athletic shoes. Actually anything that they have listed as "on-sale" and advertised in their weekly advertisement is a good deal if the size is right for you and you like the model.
As to firearms. I have purchased a Winchester Model 70 30-06 on sale from Big 5, a Remington Wingmaster 20 guage pump shotgun on sale, and an MN 1891/30 on sale. All of them have performed well. They had a great sale on Model 70's but I had to have them call and track down a 30-06 for me in another county and go to that store for get the rifle I wanted. They didn't want me to open more than one box to look at an MN 1891. I found an open box and so got to choose between the best of two that I could look at.
In most stores (I have purchased firearms at three Big 5 stores) the sales people don't have any real knowledge about firearms. Generally this is not a store to go to if you need help selecting ammo, or are having them mount a telescopic sight. It is also not the store to go to for anything that is not on-sale. When I bought my MN 1891/30 they had Wolf ammo for it going for around $7 per box of 20. I can buy Wolf ammo a lot cheaper at gun shows or over the internet.
Let me be clear about their prices. I have gone in to Big 5 and found MN-1891/30 selling for $149.99 and thanked my stars that in the following week's adds they were selling them for $79.99, so I purchased when it was on sale. I have seen MN-44's with price tags at $149.99 and seen them on sale the next week for $79.99. Everything seems to be on sale at least once a month.
Big 5 seems to sell whatever Century Arms Importers is pushing. I have seen Big 5 sell Russian Bolt action MN's, Yugo Mausers, and Swiss straight pulls. They seem to go for the bolt actions and less expensive firearms. They have good sale prices on Remington, Wincheser and Savage rifles as well as Ruger 10/22's. The stores I have gone to have had poor ammo selections.
I will not buy ammo or accessories at Big 5 and limit my interest to only what is advertized in their weekly flyer. Otherwise, they are great.