It's just a bit strange 'cause RE3 remake seems to be sitting in Steam here asking for A$93. Now, as far as Ive bee told, it's a pretty big overhaul. But $93?Ok, no, I was misunderstanding your questions. I interpreted your first question as "what would Nintendo charge for a remaster" and your second as just asking confirmation that 3D All Stars costs $60 for 3 remastered games (tho actually seemingly 2 + a straight port), and that the two were unrelated questions. Sorry, haven't had enough caffeine yet to get my brain up to full speed.
Anyway, to answer your last question: I suppose $20 per game is ok if you've never played any of these games before, or if you badly want to be able to play them on the go. I do think $60 is pretty high compared to similar remaster collections, the majority of which are in the $30-40 range, and some of which are full on remakes (like Crash/Spyro), and could be seen as arguably better value propositions. Tho Nintendo's adamant stance on basically never dropping the price of their games is well known, hence the "It's Nintendo. So 60 bucks" from earlier, so it's no surprise they're charging 60 for 3D All Stars, which in a sense is sort of generous by their standards.
On a personal level, no, not worth it to me. But that's cuz I already have all 3 and can do superior remasters.
I dont think I've bought a remaster but Ive always thought they were overpriced