You're living in a fantasy world if you think really good rain gear can be found cheap.
The low end range is either pvc (doesn't breathe and is worse than nothing), low end polyurethane coated nylon (doesn't breathe and is hard to put on), or tyvek (not durable). I've wacthed folks destroy those cheap yellow suits sold at big box stores on the first ride from wind flapping.
The best gear breathes well enough to be comfortable for an all day ride on a hot humid day and lasts as long as you care to use it. Provides total protection, of course.
, there are only two things in this category- GoreTex or a copy equivalent- used either as a minimum weight membrane piece or mfd with a fabric outer meant to improve durabilty.
Prices for such stuff are $70-140 per top or bottom piece.
I use both types.
My membrane type GoreTex stuff includes a 30+ yr old LL Bean jacket and a current Cabela's Pac-lite. I finally wore out a set of 30 yr old GoreTex pants and replaced them with GoreTex Pac-lite from Cabela's because they are available in long length to better suit sitting on a bike.
A good combo type is the Tourmaster stuff with plenty of reflective material on it. SO uses it and likes it and I carry a set for car and outdoor use- doesn't pack down as small as GoreTex membrane stuff. Roadmaster used to make some good stuff of this type- don't know if its still available.
Re hoods- depends on the bike type. On my RT I never use the jacket hood- not needed. Might say different if I rode a naked.
A 1 piece is harder to put on than a two piece but some good one piece items can be bought for less than the combo price of a two piece set. The BMW 1 piece seems to be well liked by its users.
Of course, if you can afford the latest high tech gear like the high end RevIt or Klim stuff built with GoreTex laminates, you don't need rain gear. Such stuff is over $1K/set but is as good as it gets right now.
Jacket liners do poorly compared to external rain gear IMO. They're OK for short runs in the wet IF they're already installed when the rain starts (a big if). Not as useful if you're doing an all day ride.