Im not really good at this but here goes, I noticed that for almost a month now my car has been having great difficulty starting up most especially if left turned off for more than 8 hrs, and any longer than that and I end up requesting people to help push the car for me to jump start it, funny thing is that even with this issue, the battery indicator has never come on, I mean it lights up when I turn the key and turns off when the car starts. I took it to a car shop, they plugged some wires, ran some tests, and the conclusions they are giving me may be true but it could also be that they may be just trying to squeeze as much cash from me as possible. At first they told me that its the battery, its too small for the car, in a nutshell they say the car consumes more power than what the battery is able to charge back, and they added that the guy who probably sold me the car just put that battery in just so he can sell it. Ok I will admit the battery looks really small, its pretty obvious because the battery compartment is bigger than the battery itself, but the thing is the car has not been giving me any start-up issues for the first year and a half so if it was a battery issue wouldn't it have had start up issues from the start? and they're next diagnosis is that there is a possible problem with the alternator, so they are suggesting that I first buy a battery from them (surprisingly they're suggesting that I get the most expensive at 8k) and then if the battery does not solve the issue thats when I get my alternator checked and possibly replaced ( lol which they also do) and I asked them that in case its an alternator issue, could I return the battery?, and they said no..... So, its not like Im calling them a bunch of crooks...yet, but it just seems a bit suspicious so I might as well get some feed back from you guys first before I do anything else, just to get other peoples opinion on this matter, Thanks

Car by the way is a Hyundai Getz, 2007, manual