Well first off welcome to the rc scene.
Like any toys with use it will brake but thank to spare parts you can always replace them. Also One might think these are toys but these toys represent like a miniature car really. There will be time when everything runs smoothly and there will be time that nothing goes right.
Your second question can they do power slide and donuts and the answer is yes, depends how the set are on the car is. Also doing donuts will damage your tires and tires are by all means the comone parts you will need to replace.
third question gas and electric cars well both have a plus and negative and both are just as expensive. So there is no cheap ones. I have both gas and electric and each of my cars cost around 1,000 to 2,000 dollars. You have to remember you will need a fairly decent remote and I am guessing you don't have. For me I needed a remote with 3 car memorry meaning One remote I can control 3 different cars. Digital servos with metal gearing cost 100 bucks each and since you need 2 per car that 200 dollars. Of course you don't have to spend that much but that is around the top of the line. with gas you will need a fairly good engine that's another 200 bucks and a starter box 50 -80 bucks. Glow stick 20-30 bucks. fuel by the gallon. and tool box to hold your tools and different set of tires from sponge to rubber. with electric you will need a motor 60-100 dollar battery pack 20-60 bucks for a pack a good quick charger 40-300 bucks, and just like gas you need toolbox spare parts etc.
Then you have your bodies and trust me wanting one will not do you will be attempted to get more then one and they go from 20 bucks to the more expensive ones which are your tamiya and kyosho bodies which goes for 30-50 bucks.
Now all those price range is assuming you want to get a car that you have to built. You could got for the rtr type cars HPI has a rtr gas and electric type, Team Associate has another one the TC series which are better then the HPI. You really need to do a good research.
Also I tell this to all my friends who wants to go into this hobby. It is not a cheap hobby so I mean if you have a tight buget I really would not suggest you going into it. And when you say a tamiya is expensive you were probably looking at their rtr cars which is by all means cheap in comparison.
I hope this answer some of the questions.