The good thing is that now you have really memorable lessons that will make you not forget to make sure all of those things are in order before flying. I was in the same boat in the beginning and now I inspect everything before every flight and if in doubt, I replace stuff (especially props). I still have issues though. There are just some things that you don't see coming. That's why I always keep extra frame parts, at least one extra motor of each size, ESCs, etc. Things are much less expensive now and you can always build cheaper to be able to keep the budget to buy extra parts. In the beginning, you don't need $40 motors and carbon fiber frames and whatnot to learn the hobby. Hell, you can get GREAT control boards now for 25 bucks.
Damage sustained from crashes do lead to other crashes - which always has me paranoid after a crash, but typically really good inspection and not taking chances will keep your odds pretty good of having a good flight ready quad after the repair. Again, unless you're actually racing or you're so good at flying that you're pushing limits, you don't need expensive props, so you can always get a ton of gemfans or whatever for a few bucks and toss them in the trash and replace them after every crash or when they start to show signs of stress, or whatever. If you do that, you should spend a couple of extra bucks on a prop balancer and you're good to go. **You may also want to use different props if you're trying to shoot really clear jello free video, but by then, you will have also probably invested a lot into other measures to make your video look good, so that usually comes down the line.
With all the crashing that happens in the beginning, my best advice is to budget your build around knowing that the thing will be crashed and repaired a lot. As far as getting practice flying, a cheap RTF is usually a good idea since it should be dialed in already. Plus when you crash your quad, the day isn't over since you can keep flying the RTF to continue practicing. Then you don't waste a trip to the flying field.