Personally, I'd wait at least a month, maybe more after your cycle and adding fish before adding coral. you want to have confidence that your tank is stable enough for them before adding coral. Fish are more hardy and can tolerate more nitrates than the coral can. And once you add your fish, your bioload will go up, and if your tank doesn't have the capacity to handle it, you can have nutrient spikes which can harm your coral. In addition to this, a newly setup tank will go through algea blooms and these can make coral care more difficult. The algea can smother the coral and cause deadspots on them. Some coral are more resistant to this than others.
I'm surprised their prices were that high. It's been a while since I've been there, but I'd have expected something to be available for $5-25. the MARSH forum is another great place to seek out cheap coral in Houston. I've gone to a member's house to get some mini starfish, and after talking to him ended up getting 8 frags off of his coral for under $50. There's lots of people who will help a fellow reefer out, but you'll always pay more at a store. hobbyists are usually just trying to help cover their costs, while a business has to pay for upkeep, rent, labor...etc. So they are in it to make a profit.
As far as CUC, for a 10g, you don't need much. I'd say just a couple of cerith snails and nassarius if you have a sandbed. you can try adding a single turbo if you start getting more algea growth, but if you don't have much they will starve. Best bang for your buck as far as cleaning algea goes. If you find you need more you can always add some. Most places will try to sell you on getting a couple dozen snails for that tank, and that's just grossly overkill, and much of your CUC will end up dying.
Remember, nothing good happens fast in this hobby. Take your time with tank changes or additions of any kind.