Seeking guidance on creating my army

I will soon acquire 500$ and wish to start my army with that budget. I can buy stuff locally at Canadian prices and not pay any taxes. What should I get? I already have the codex.
I'd mostly aim at raiders/ravagers and reavers, because I love the models.

I plan to start my army shortly with two battleforce sets. Two raiders, twenty kalabites, twenty wyches, and six reavers for $220 USD...or less if you know where to shop? Yes please!

The above plus a couple more Raiders, some Venoms, and some Ravagers is really a pretty excellent starting point.

I would submit that perhaps the best plot is to figure out what point total your local games are mostly played at, and then you could have a good idea of what scale you'll be needing to aim at.

Mostly switching between 500, 750, 1000 and 1250.

First thing to decide when your starting your army is finding what style of play you find the most enjoyable. You've haven't mentioned what style you prefer so I would advise playing a few games with proxies just to try out different lists before you commit to buying. That said raiders and venoms are pretty much a must have in most armies so they are a safe bet to start with.

Personally I play Kabal lists and have found them to be very effective. Reavers look abosolutely gorgeous, the bladevanes make for great fun and they are fairly good for objective contesting. Ravagers are pretty solid anti-tank, though I would recommend a flyer as a heavy support slot. I have also found coven to be quite effective in the 500pt tournaments I have played, wracks are pretty durable and grotesques are a pretty effective beat stick if you stick them in a raider with a Killy archon/succubus.

For the points sizes you are likely to be playing I would recommend getting 2-3 raiders and 2 or so venoms this should give you some nice options at each point level and allow you to experiment and change between the various types of lists with relative ease. Aside from that I cant really advise much other than to try out various combinations to find out what works for you before buying models. Hope that's in someway helpful...

As first two responses, but with the added obvious Archon that they're missing.

For the Archon I guess I could just convert it from bits of witches, kabalites and green-stuff cloaks.
Especially given the very dynamic poses some will have when coming from a vehicule box!

Cart so far:
Battleforce
Raider x2
Ravager x2
Razorwing Jetfighter
Kabalites
Reavers

Incubi are always worth a second look. They slice to virtually everything. And the models are cool.

Battle force is the only real deal basically means a free unit for the cost of three, given that you are looking at an additional raider, reavers, and kalabites I'd snag a second battleforce for a free unit of wyches. Looks like a good purchase though.

Yeah - since you want Reavers, Raider and Warriors in addition to the battleforce I would agree and say get two battleforces.

Don't forget to leave money in your budget for the transport cases. Unless your getting a discount for making a large purchase, start small. The suggested two battleforces, plus a Ravager and an Archon is plenty to start with. After that, play some games and you will get a better feel for what you want to add next.