Really depends on the kit. I tend to buy from Etamiya.com because their prices are far cheaper than squadrons 'suggested' price, though the shipping is expensive. I stock up on a few kits at a time since it's flat shipping up to 990grams or something so it works out.
I found that Tamiya makes a ton of modern aircraft in 1/72 scale, a few in 1/32 with insane detail and then their 1/48 are dominated by warbirds. So if I get into a warbird itch, I would likely migrate to 1/48 scale, but if I can choose, I like 1/72.
I've seen the Trumpeter A-10 with the really sweet cannon, and I've seen it inside the airplane(well, SEEN isn't the right word, because you can't see it). I've built a cheap 1/72 kit for 80 dollars less that from 3 feet away looks almost identical to the 1/32 Trumpeter makes.
I would however like to point out that the process in building the Trumpeter A-10 is probably leaps and bounds ahead of the cheaper 1/72 kits you can find as far as the fun of building it goes. Three sprues or 10 with 900 parts? Hmm guess it depends on if you're lazy or someone who likes instant gratification, hehe.
However, only the person building the kit and other afficiando's and/or contest judges are studying it 6 inches from their face. Looking at my display case full of 1/72s with a 1/32 in the mix will still look awesome from my Lazy-Boy regardless.
I lean towards 1/72 I guess(I just went on a 1/72 shopping spree at etamiya and when I get that package of 4 kits I'll salvitate -- were I to buy a single 1/32 from them it wouldn't feel like a shopping spree... four 1/72 kits or 1 1/32, tough choice!). But once in a while I wouldn't mind dropping the 100$ or so on those nice Tamiya 1/32 kits or the Trumpeters.