I'll disagree flatly with Jack on ii and somewhat on iii.
Hooters food is not "shit," as judged by someone who's presumably not an American. It is a kind of American comfort food/fast food that bears a pretty good resemblance to what you'd get at Hooters back in the U.S. So at least in that regard, they're being reasonably authentic here in BKK. And, like most things here done here in farang style with imported ingredients, the prices are going to be higher.
I've had a couple of their hamburgers at the Soi 15 branch, and they've been better than average for Bangkok. Mainly, the beef Hooters uses here has been tasty and a good grind, not some of the foul-tasting (Thai?) beef that too many places around here use for their burgers. When I went, it was with a 50% Eatigo discount for the Soi 15 location. But that's ended now, and neither of the BKK locations are running those Eatigo discounts anymore AFAIK. So, it was a good deal for me at around 250b (half off), but not so good at full price of close to 500b.
Second, as regards the price, needless to say, you're paying a premium at Hooters -- whether back home in Texas or here in Bangkok -- for being served and tended to by the "famous" Hooters girls -- although most of the Thai staff I've encountered at their Suk Soi 15 branch, while youngish and cute, haven't been particularly well-endowed with their Hooters -- at least compared to their American Hooters sisters.
I don't know if there's really a viable market for Hooters on Suk Soi 4. But, at least, Hooters is very clear and upfront about what kind of business they're running -- American comfort food and drinks at above normal prices served by cute eye-candy girls/women mostly of the look but don't touch variety. That either appeals to someone or it doesn't. Simple as that.