Here's the kind of receiver that I have......an ICOM IC-R2.
Click on Icom receivers (5 down), then click "Our Receivers" and the first one shown is the IC-R2.
Here's were I got it from. This site will give you an idea of what these receivers cost at retail prices. Unfotunately mine isn't on their website. I think it's because they just started selling them. I got it as a gift in mid November and it costs over $400 Canadian.
Regarding your question about whether you need permision or not to have a receiver......the answer for up here in Canada is NO. I will tell you though, that it's quite normal to have airport security or local police approach you if you're at the end of a runway holding a receiver or transceiver in your hand, because they know you could be a major pain in the ass if you were an idiot and started transmitting commands to pilots.
I've been approached at Toronto Intl a few times while spotting since 911, but I was also approached by the RCMP (Royal Canadian Mounted Police) on many occasions 20 years ago when I would borrow my father's receiver and watch airliners at YYZ all day.
Regarding your question about which ones have the "best bang for your buck", well, I couldn't tell you, because my new receiver was a birthday gift from my girlfriend, so I wasn't involved in it's purchase. I'm still trying to figure out how to use most of it's features. The instruction manual isn't that user friendly.
PS, I don't mean to sound like I'm bragging about this receiver, however, I sure do love it. You've probably noticed that a lot of my questions over the last week have been sparked by things I've heard over this receiver. Well, so was the next one I'm going to post about a JAZZ Dash-8 that had landing gear problems this morning.
I hope you get a receiver soon Bio15....you will have a "blast" with it!