So, my questions are- Is that an ok price (did i get ripped off) and are they an ok brand?
You didn't get ripped off.....they're usually $17-$20 ish. Look Peapods don't get a great rap, but I started with them and they suited us just fine. The red one sucks cos they always leak, but the other colours are fine. I still use my boosters (the pockets dies long ago) and they are nealry 3 years old

Do I really not need to soak them?

Don't if you don't have to. It ruins the elastic

can I really throw them in with the rest of my wash?

Yep, If I've only got wee ones I do. Poo i don't though. But we go through enough that there is enough for a load on their own at the end of two days.

Can I really put them in the dryer?

You can but sun is better for the PUL and the elastic in the long run

And if I decide to go full time, how many will I need?

how many times a day do you change her? Add a couple of extra and work out how many days you want to wash. I've had plenty in my time. Nate had up to 60 in rotation to start with. I've culled and we're probably down to about 30 I reckon....but I love them and have had them since DD was small.

And what's with the liners?

I only use liners (micro fleece not disposable or flushable) if he's sick with gastro or got nappy rash.

There are heaps of online stores. It also depends on the make of your bub as to what works best. SOme of the nappies everyone else love on here just don't suit Nate, whereas I have a few that others don't rate.