don't you think money would play a factor if it were to be possible. Look at NYFC for example being backed up by Manchester City and the Yankees. I understand NFL teams don't pop out out of air. But perhaps, pick a city with a strong football history (College etc) and start buying and recruiting.
NFL stadiums are massive though...it seems like a huge feat
Yeah, US Sports don't work like that, infact, I could be a Multi-Millionaire and buy a team and relocate them to Alaska if i could prove that the NFL would make money. NFL is a money making machine, so you'd need an owner willing to sell and the NFL agree to the move i.e. You couldn't just buy the Packers and move them to somewhere like New York where there would be little appeal due to other teams being there, or move them to somewhere like Boise, which would be disasterous.
Money of course plays a factor, but only in effectively buying the opportunity to relocate, and on the NFL's terms, hence why they are willing to wave it in case of the Rams/Raiders/Chargers, because they're so desperate for an LA franchise.
MLB, are looking into a possible introduction of 2 more teams to make all leagues similar to the NFL, however if you're looking at being a fan of a new NFL franchise, don't be thinking it's going to be anywhere but LA or San Antonio.