An 18" dish is only going to bring you the FTA dbs channels/satellites, so about all you will get (if you have line of sight) would be music channels, Gol TV, Nasa and a few test/info channels, I would say 90% of the FTA hobby is Ku band, for that you would need a 30" minimum sized dish, on a perfect day pointing at a strong satellite you may just get by with say a 24" dish but you would soon get fed up with your reception if it starts to cloud up or rain.
A great starter receiver would be the Satwork 3618 (IMO) thats what I have it it is VERY simple to operate, just point at the satellite and do a blind scan, and it finds the channels for you! If you intend to add a motor the Satwork 3688 would be my choice, the Satworks are MUCH cheaper than the much talked about Pansat receiver.
I would say its your call, I would rather have some FTA dbs channels than nothing I guess, but you would be missing out on most of the FTA channels up there in ku band, for around $165 you can get a basic receiver , 30" dish and ku band LNB, that may be the cheapest way into the hobby and you will not be out of pocket too much, and the dish could be stored away in case you ever move, thats another thing they should not be able to stop you getting a 30" dish, they are not much bigger than say a 24" dish, and the dish can be painted or there are new dish covers available that slip over the dish, they come painted with wood or brick effect on them, hope this helps a bit.