Guys, are these widespread interps? Yukari's one of the best damage dealers for the majority of the game (pretty much until Amps start showing up, since her stats make up for the lack of Boost)
They really don't. Even with just Boost, in-game she was consistently below Mitsuru and even -Koromaru- for her offense, which I'd instantly peg as "below average damage". Floor 1-3, she's solid enough, but she both gets the higher-level spells a bit later than other PCs -and- never gets boosts and amps. The high magic stat doesn't compensate for the multiplicative boosts.
Yosuke has solid damage of both types
"Solid" as "middling 3HKO as its absolute best", and he sees a gigantic lull in his physical damage. Until floor 6, he's stuck with fucking Sonic Punch for physicals, and that starts sucking at floor 3! Due to the stupid physical offense jumps starting floor 6, he dips from "averagish" to "5HKOs unless he wears Auto-Taru armor", and that's not what you want in a team whose offense is already anemic.
and Teddie joins in F3, when his damage is absolutely fantastic, and Matarukaja is Lv 42, with the end of F4 being Lv 45. (Maraku-, on the other hand, is probably F6.)
Okay, my bad on Mataru, L42 is a -lot- better than I thought. I'd dispute his offense being fantastic, though: he doesn't start with Ice Boost at a point where PCs start getting it. Earlier game, the damage averages are also quite tight, so you don't see huge damage leads either. I don't think he'll ever 2HKO anything at -any- point in the game without buffs.
I can't really comment on Demi, since I've barely played PS4, but if these interps are pretty common, then I'll have to change my team and.. probably all of these three need lower prices, because shit, this makes them practically useless.
Well, Demi... her immunity to attack buffs doesn't come up often, because that's really not what she's about, and her perks honestly make up for her deficits (Medic is absolutely hax, MT revival and full status healing is a bailout of doom and destruction even if the healing isn't that good, and mdurability buffing that's MT, powerful, permanentand persists through death = holy shit that's amazing. PS4 defensive buffs are some of the bestest things ever). As for Yosuke/Yukari/Teddie pricing... honestly, I consider both Yosuke and Teddie overpriced. Wingman just doesn't cover niches very well and the Thunder weakness for the first three floors can spell instant loss to a team because P4 weaknesses are broke as fuck against you. Teddie has -that- issue for the whole game and frail, slow healers are a huge whatever (on the other hand, you really don't have much lower to go from 1.5 >_>. And Teddie has -some- perks. Matarukaja isn't that potent a buff at base, since it's not even quite 1.5x to damage, BUT it affects both offenses, and -this- is hard to come by and can see itself slapped into a lot of parties). Yukari... well, without that weakness, she'd be worth a 1.5, probably, maybe even a 2.0, the healing skillset is quite potent - she's kind of a Nina4-lite, and look at how Nina4 fares herself. P3 weakness doesn't spell QUITE as much doom for a whole team either, even if it's considerably worse individually.
Ultimately, though, I think you just emphasized putting in people with crippling elemental weaknesses too much. Just because you can have a move that immunes one casting of that weakness doesn't mean you should pile them up like that, especially when three of those people give the opposition extra turns to work with when slapped around. One suggestion could be keeping Yuna and Teddie, slapping him with Body Charge (suddenly he looks very attractive with 30% more durability, damage and speed for only 2 points, and even if his damage needs work by the end, the MT emphasis off non-liability quickdrawing power is a nice boon), then building up the team's strengths with other PCs.