Buying a gun online - like a Python - that you can't hold in your hands and inspect closely ...is really foolish in my opinion.
Yep, if you have to ask, you have some learning to do son.
TBS, I did buy online, a new S&W 627 (.357 mag 8-shot) V-COMP for $1200+ OTD (MSRP $1700+). This was a factory backed up gun from a S&W retailer. I'm golden with that. Good luck